Remove tabs

Accidentally let a couple of tabs in here. Keep the HTML to just using
spaces.

Change-Id: Ieed28d5d8b18c984fdc2ce4be7308901f082eccb
Update tagline

Change-Id: Idd110e0f689139fecd102a57e8ae6d60b3ecf6b4
Minor formatting change

Change-Id: Id3ff655013787ca52a66648c482cc6e0ac87ef2f
Remove smart quotes

Avoid generating "smart quotes" when translating markdown into HTML.

Change-Id: Ic807157d24df50dd3913d5e631d741fa32fb29e0
Add 'support' page

Add a prototype 'support' page, for donations, volunteering, etc. Many
links and some info in here is missing, but will be filled in later.

Change-Id: I9432bc943070f79d4b1f9dc825ef6209631d035a
Update list of official documents

I don't have most of these documents yet, but at least list what is
supposed to be here.

Change-Id: Ia35f8d6e8ecfdd423ee940ab95843aa920ad1f50
General updates

This just adds some more content based on feedback received over the
past few weeks. Most broken links are now resolved; the remaining ones
are just for documents I don't have yet.

Some minor visual tweaks are also included in this, unfortunately
mixed in with content updates (sorry).

Change-Id: If291079bc46559c56c22d942ea2270a544e9a01d