Document how to build SQLite with this extension

[benwebber]

Instead of linking to the extension, we can also compile it with SQLite.

• Document how to include the extension in the SQLite source tree
• Add a CI builder for the built-in version

From #3

[speg]

Yes please!

I'm developing on macOS and trying to statically link SQLite into my program.

When I go build my program on Ubuntu it doesn't include the uuid extension 😥

The compiled world is alien to me, but from what I gather I need to build a version of SQLite with the uuid extension included, then link my program to that?