Re: README.md files per directory

[snip]

Ok, I've figured out how to ingest markdown files, which addresses
Farhan's suggestion /and/ my desire to write docs that tie into
doxygen generated stuff.

https://reviews.freebsd.org/D56652

The diff needed to mark a file as the default (which you dont have to
do, I think I can also just add \\mainpage to the top of README.md or
something like that)
and have it not generate the default template is pretty easy:

```
diff --git a/tools/kerneldoc/subsys/Doxyfile-net80211
b/tools/kerneldoc/subsys/Doxyfile-net80211
index f9ce81e4ca06..6f9eccc73185 100644
--- a/tools/kerneldoc/subsys/Doxyfile-net80211
+++ b/tools/kerneldoc/subsys/Doxyfile-net80211
@@ -9,7 +9,8 @@ EXTRACT_ALL            = YES    # for undocumented
src, no warnings enabled
 #--------------------------------------------------------------------------
 # configuration options related to the input files
 #---------------------------------------------------------------------------
-INPUT                  = $(DOXYGEN_SRC_PATH)/net80211/ $(NOTREVIEWED)
+INPUT                  = $(DOXYGEN_SRC_PATH)/net80211/
+USE_MDFILE_AS_MAINPAGE = $(DOXYGEN_SRC_PATH)/net80211/README.md

 GENERATE_TAGFILE       = net80211/net80211.tag

```

I'll work on some initial net80211 documentation just as a proof of
concept and see how it plays out.



-adrian