Update tutorial.

Update version

A lot of progress has been made:

 - Better rendering.
 - Multiple cursors.
 - Key bindings.
 - Dumb auto-indenting.
 - Removed Lua.

But we still have a long way to go:
 - We still don't have a tilable interface.
 - No easy way to open files.
 - No way to open directories.
 - No system copy buffer integration.
 - No extensably or configurablity.

More up-to-date screenshot