Replace gf-refman.html with Markdown version gf-refman.md

The raw HTML was invalid, and this way we use the common website template
for a uniform look without any duplication.

It seems gf-refman.html was once generated from txt2tags, although I have
been unable to find this original .t2t file.
I also tried to re-generate txt2tags from HTML but was not able to.
However I was able to convert HTML to Markdown using Pandoc and I think
the result is pretty good, so I think we should use this.

The original gf-refman.html can be obtained from git history, e.g.:
a7e43d872f/doc/gf-refman.html

.gitignore

@@ -54,7 +54,7 @@ doc/gf-bibliography.html
 doc/gf-developers.html
 doc/gf-editor-modes.html
 doc/gf-people.html
-doc/gf-reference.html
+doc/gf-refman.html
 doc/gf-shell-reference.html
 doc/icfp-2012.html
 download/*.html

bin/update_html

@@ -93,10 +93,18 @@ function render_md_html {
   html="$2"
   relroot="$( dirname $md | sed -E 's/^.\///' | sed -E 's/[^/]+/../g' )"
 
+  # Look for `toc: true` in metadata (first ten lines of file)
+  if head -n 10 "$md" | grep --quiet 'toc: true' ; then
+    toc='--table-of-contents'
+  else
+    toc=''
+  fi
+
   pandoc \
     --from=markdown \
     --to=html5 \
     --standalone \
+    $toc \
     --template="$template" \
     --variable="lang:en" \
     --variable="rel-root:$relroot" \