Evolve website documentation repo?

[Matt Harbison]

Is there a repo (or other mechanism) for updating the pages here?

	https://www.mercurial-scm.org/doc/evolution

The front page looks like it was updated recently, but the other pages are  
about a year and a half old, still reference old vocabulary and temporary  
amend commits, etc.  I don't mind taking a stab at it (though I don't know  
how the diagrams were generated).