support toml metadata

[blaenk]

So I found out about markdown-use-pandoc-style-yaml-metadata a little late. It's great because I use front matter metadata.

However, it seems like new static site generators are now also using or accepting TOML, including one that I'm working on.

In order to get this working with my TOML metadata I simply had to add = as a possible key-value delimiter. I wonder if you'd be open to making this change, since it seems to be pretty minimal and I don't believe it would conflict with YAML metadata since that uses :.

If you're against this, I'm currently hacking it in myself by setqing the markdown-regex-multimarkdown-metadata regex. Is this the best way to go about it?

--- /home/blaenk/.dots/emacs/.emacs.d/inits/languages.el
+++ #<buffer languages.el>
@@ -102,7 +102,7 @@

   :config
   (setq markdown-regex-multimarkdown-metadata
-        "^\\([[:alpha:]][[:alpha:] _-]*?\\)\\(:[ \t]*\\)\\(.*\\)$")
+        "^\\([[:alpha:]][[:alpha:] _-]*?\\)\\([:=][ \t]*\\)\\(.*\\)$")

   (add-to-list 'markdown-gfm-additional-languages "cpp")
   (add-to-list 'markdown-gfm-additional-languages "elisp"))