Currently all the headings marked as `#` show up
as a top-level entry in the `Developing LLDB`
toctree. This patch marks these as `##` so only
`Adding Programming Language Support` is displayed
in the table of contents.
This got deleted in e078c9507c3abb4d9bb2265c366b26557880a3e3, I presume
accidentally, because it didn't have a corresponding rst file for it.
So I've brought it back and converted it into Markdown. The content
remains accurate, from what I know at least.
It's a bit "now draw the rest of the owl" but if nothing else, it gives
you a bunch of important classes to go and research as a starting point.
You can see the original content here:
5d71fc5d7b/lldb/www/adding-language-support.html
