Patch to bring KSudoku Handbook up to date

--- index.docbook.orig	2020-05-21 16:25:23.000000000 +1000
+++ index.docbook	2020-05-22 15:41:44.000000000 +1000
@@ -82,7 +82,7 @@
 	symbol. In &kappname; the symbols are usually the numbers 1 to 9,
 	but may be the letters A to P or A to Y in larger puzzles. Puzzles
 	start with the board partially filled and it is your job to fill
-	in the rest.</para>
+	in the rest. Some types of puzzle have less than nine symbols.</para>
 
 <para>When you start a game, you can choose from several Sudoku types
 	and sizes. You can then have &kappname; generate a puzzle for
@@ -91,7 +91,8 @@
 	&kappname; to check it and maybe solve it.</para>
 
 <para>There are many variations of Sudoku in existence and &kappname;
-	provides a good selection of them. The most common variant has
+        provides a good selection of them. The most common type, Standard 
+        Sudoku, has
 	a 9x9 square grid and uses Arabic numerals 1 to 9 as symbols. The
 	grid has 9 rows and 9 columns and is divided into 9 blocks of
 	3x3 squares. The problem is – each symbol can only be used once
@@ -197,7 +198,9 @@
 
 	<itemizedlist>
 	<listitem><para>Knowledge of mathematics or language is not required
-		to solve &kappname; puzzles.</para></listitem>
+		to solve &kappname; puzzles, but a little ability with 
+		arithmetic is needed in Killer Sudoku and Mathdoku 
+		puzzles.</para></listitem>
 	<listitem><para>The symbols already on the game board when the
 		puzzle starts cannot be changed.</para></listitem>
 	<listitem><para>You can only modify the symbols you have previously
@@ -218,14 +221,49 @@
 		and 9 square blocks of size 3x3.</para></listitem>
 	<listitem><para>Other sizes of Standard Sudoku are 4x4 (very easy),
 		16x16 and 25x25 (not so easy).</para></listitem>
-	<listitem><para>The Jigsaw variation is the same as Standard Sudoku
+	<listitem><para>The Jigsaw and Aztec variations are the same as 
+		Standard 9x9 Sudoku 
 		except that some blocks are not square.</para></listitem>
 	<listitem><para>The XSudoku variation is exactly the same as Standard
 		Sudoku with an additional requirement: the two main
 		diagonals must also each contain the symbols 1 to 9 once
 		and once only. &kappname; highlights the diagonals to make
 		this easier to see.</para></listitem>
-	<listitem><para>The Roxdoku variations are based on cubes in three
+	<listitem><para>The Nonomino 9x9, Pentomino 5x5 and Tetromino 4x4 
+		variations are the same as a Standard Sudoku 
+		except that some blocks are not square.</para></listitem>
+	<listitem><para>The 6x6 variation is the same as a Standard Sudoku 
+		except that the blocks are 
+		six 3x2 rectangles.</para></listitem>
+	</itemizedlist>
+</sect1>
+
+<sect1 id="samurai"><title>Samurai Puzzles</title>
+	<listitem><para>The Samurai Sudoku consists of five Standard Sudoku
+		puzzles of 9x9 squares each, overlapping at the corners
+		by four 3x3 blocks. Each of the five puzzles has 9 rows,
+		9 columns and 9 blocks to solve and the symbols in the 
+		overlapping squares must fit into the solutions of two 
+		Standard 9x9 Sudokus.</para></listitem>
+	<listitem><para>The Tiny Samurai Sudoku contains five 4x4 Sudoku
+		puzzles, overlapping at the corners by four squares. Each
+		of the five puzzles has 4 rows, 4 columns and 4 blocks to
+		solve.</para></listitem>
+	<listitem><para>The Windmill variation consists of five Standard 9x9 
+		Sudoku puzzles, overlapping at the corners by two 3x3 blocks. 
+		It is like a Samurai Sudoku, but the central 9x9 Sudoku is
+		harder to see. Eight of its 3x3 blocks are shared with the 
+		sails of the windmill and only the central 3x3 block is not.
+		</para></listitem>
+	<listitem><para>The Sohei variation is another Samurai type and has
+		four 9x9 Sudoku puzzles, overlapping at two corners by a 
+		3x3 block. the central 3x3 block of the puzzle is empty.
+		</para></listitem>
+	</itemizedlist>
+</sect1>
+
+<sect1 id="roxdoku"><title>Roxdoku 3D Puzzles</title>
+	<listitem><para>The Roxdoku variants are based on cubes in three
 		dimensions, but are easier than they sound. There are no
 		rows or columns. A 3x3x3 Roxdoku puzzle has 27 small cubes
 		arranged into a larger 3x3x3 cube. This contains nine
@@ -233,15 +271,58 @@
 		the square blocks that must be filled with the numbers
 		1 to 9. A 4x4x4 Roxdoku has twelve 4x4 slices and a
 		5x5x5 Roxdoku has fifteen 5x5 slices.</para></listitem>
-	<listitem><para>The Samurai Sudoku consists of five Standard Sudoku
-		puzzles of 9x9 squares each, overlapping at the corners
-		by four 3x3 blocks. Each of the five puzzles has 9 rows
-		and 9 columns to solve, but there are only 41 blocks to
-		solve, rather than 45, because of the overlap.</para></listitem>
-	<listitem><para>The Tiny Samurai Sudoku consists of five 4x4
-		puzzles, overlapping at the corners by four squares. Each
-		of the five puzzles has 4 rows, 4 columns and 4 blocks to
-		solve.</para></listitem>
+	<listitem><para>The Roxdoku Twin variant has two 3x3x3 Roxdoku 
+		puzzles sharing a corner. The corner piece must be part of 
+		the solution of both 3x3x3 cubes.</para></listitem>
+	<listitem><para>The Double Roxdoku variant contains two 3x3x3
+		Roxdoku puzzles sharing three pieces along an edge. The
+		edge pieces must be part of the solution of both 3x3x3 cubes.
+		</para></listitem>
+	<listitem><para>The Samurai Roxdoku variant has nine 3x3x3 Roxdoku
+		puzzles. One is at the centre and the other eight 3x3x3
+		cubes overlap it, one at each of the central cube's corners. 
+		Those corner pieces must each be part of the solution of
+		two 3x3x3 cubes.</para></listitem>
+	</itemizedlist>
+</sect1>
+
+<sect1 id="killer"><title>Killer and Mathdoku Variations</title>
+	<listitem><para>Killer puzzles have two variants: Tiny Killer 
+		(4x4) and Killer Sudoku (9x9). They both have rows, columns 
+		and square blocks, exactly as in Standard Sudoku puzzles 
+		and following exactly the same rules. They also have 
+		irregularly shaped areas called cages, where each cage's 
+		digits must add up to the number in small type in the 
+		corner of the cage and no digit can be repeated within 
+		the cage. Typically the puzzle starts with only a few 
+		squares containing symbols. You need to use arithmetic 
+		and the usual Sudoku rules together to work out the 
+		solution. The screen graphics make it difficult to 
+		visualise the square blocks that are present, but they 
+		are easier to see if you print the puzzle, using the 
+		<menuchoice><guimenu>Game</guimenu>
+		<guimenuitem>Print...</guimenuitem></menuchoice> 
+		menu item.</para></listitem>
+	<listitem><para>Mathdoku variants, also known as 
+		Kenken</trademark>, have no blocks, only row and 
+		column restrictions, and have cages where the digits 
+		must add, subtract, divide or multiply according to the 
+		values and arithmetical symbols in small type in their 
+		corners. A digit in a Mathdoku cage can be repeated, 
+		but not in the same column or row. For example, an 
+		L-shape of three squares with a requirement 5+ can have 
+		solutions 1 3 1 or 2 1 2, provided the ones or twos are 
+		not in the same row or column as each other. Note that 
+		subtraction and division cages always have two squares 
+		and the two digits of the solution can appear in either 
+		order. For example, a 2- cage could have solutions 1 3 
+		or 3 1 or 2 4 or 4 2, etc.</para></listitem>
+	<listitem><para>Because there are no blocks in a Mathdoku puzzle, 
+		it can have any size from 3x3 up to 9x9, with the default 
+		being 6x6. See the
+		<link linkend="configuration">Game Configuration</link> 
+		section for details. To get you started, there is 
+		a variant called Mathdoku 101 of size 4x4.</para></listitem>
 	</itemizedlist>
 </sect1>
 
@@ -529,6 +610,10 @@
 			<listitem><para>Toggle the &kappname; highlight option for three-dimensional puzzles.</para></listitem>
 		</varlistentry>
 		<varlistentry>
+			<term><guilabel>Mathdoku puzzle size (3-9)</guilabel></term>
+			<listitem><para>Choose a size for Mathdoku puzzles, from 3 (very easy) to 9 (very hard) with size 6 being the default..</para></listitem>
+		</varlistentry>
+		<varlistentry>
 			<term><guilabel>Settings for 3-D Puzzles Only</guilabel></term>
 			<listitem><para>These five settings adjust the highlighting and visibility of cells in three-dimensional puzzles. The idea is to make it easier to see relationships between cells, especially if they are behind other cells.</para></listitem>
 		</varlistentry>