Package build and corresponding documentation

I am trying to make the documentation makefile for a package of mine.
Using emacs documentation as guidance, I see that Makefile.in uses
srcdir=@srcdir@.  This implies to me that srcdir=@srcdir@ is an autotools 
substitution placeholder in configure.ac or Makefile.am.

Would I need to have a configure script for my package?  And use 
autotools so I can place some settings in configure files (configure.ac)
or Makefile.am?

Currently I have one file called antares.mk.