docs: Add a Testmonials page.

Show our positive reviews to the world. It's also not completly serious, in a similar fashion to
Phabricator.

docs/testimonials.md

@@ -0,0 +1,39 @@
+# Testimonials
+
+## Read what users and developers have to say: 
+
+> I'm surprised when it works
+
+Martin von Zweigbergk, project lead who contributed over 100k lines of code.
+
+> Jujutsu is pretty cool, you can even keep most of your existing workflows 
+
+Ben, who really doesn't want you keeping your existing workflow.
+
+> I'm sometimes still surprised that the navigation works.
+
+Philip, initial contributor of `next` and `prev`. 
+
+> Who are you? What are you doing at my house?  
+
+Austin Seipp, contributor.
+
+> Wait, it's not called Jujitsu?
+
+Phil, a Mercurial contributor and user.
+
+> It's the easiest time I've ever had learning a tool this deeply this quickly, 
+> because of the ability to experiment and undo, instead of triple-checking 
+> before trying a new scary command.
+
+An anonymous user.
+
+> Jujutsu is amazing because it trivializes some of the things I couldn't have come 
+> up with anything remotely as elegant. 
+> It's so rare that a solution attacks the innermost core of a problem so 
+> thoroughly, I genuinely feel blessed to be in its presence. And also a bit 
+> vindicated in not even trying to learn to use any of the tools that felt like
+> more crutches stacked upon a sand castle  
+
+Another anonymous user.
+

mkdocs.yml

@@ -84,6 +84,8 @@ nav:
 
 - "CLI Reference": 'cli-reference.md'
 
+- Testimonials: 'testimonials.md'
+
 - Concepts:
       - 'Working Copy': 'working-copy.md'
       - 'Branches': 'branches.md'