Add links to Jsonnet user Tweets and blog posts on the website

[mbrukman]

Some potential user reviews to include on the website / in a tweetstream:

• https://twitter.com/brett_viren/status/1012799324932268032
• https://wirecell.github.io/news/posts/pgrapher-configuration-improvements/ (linked from above Tweet)
• https://twitter.com/rxin/status/1012031650279182344
• https://qiita.com/yugui/items/f4a5e0e9dbd8ddffa48e (in Japanese)

and, of course, these well-known blog posts:

• Databricks blog post
• Bitnami blog post

Some others for consideration:

• Jsonnet used for Apache Aurora configuration
• HN thread on Jsonnet

[lukesmurray]

I think an even higher priority is adding installation instructions. It could be as simple as writing brew install json somewhere on the homepage and adding a link to the readme or to the bindings section for operating systems other than OSX. For anyone who doesn't follow the link to github it's not immediately obvious from looking at the front page that this project has a public installation available.