I have no idea if this is going to cause rendering problems, and it is fairly
hard to check. So let's just merge this, and if it github markdown processor
doesn't like it, revert.
I think it makes sense to keep the "The" in place for the actual page's
title, but let's drop it from the categorization header, to make it
easier to find stuff, as the "The" isn't helpful to that.
In particular as we sometimes do it this and sometimes the other way so
far, hence let's stick to one common rule.
It turns out Jekyll (the engine behind GitHub Pages) requires that pages
include a "Front Matter" snippet of YAML at the top for proper rendering.
Omitting it will still render the pages, but including it opens up new
possibilities, such as using a {% for %} loop to generate index.md instead of
requiring a separate script.
I'm hoping this will also fix the issue with some of the pages (notably
CODE_OF_CONDUCT.html) not being available under systemd.io
Tested locally by rendering the website with Jekyll. Before this change, the
*.md files were kept unchanged (so not sure how that even works?!), after this
commit, proper *.html files were generated from it.
