Readme imrovements

[DavidBarry]

These are a couple minor changes that should help improve the README a bit.

• I used the appropriate language identifier for code blocks so that you get syntax highlighting on those.
• I also updated all references to the documentation in the readme to link to a rendered version of it.

For the documentation links I used htmlpreview.github.com to link to the rendered docs instead of the raw html. It seems like setting up GitHub pages to host a set of the docs is probably the better way to go but this will give you a viewable version of the docs in the browser in the meantime.

Let me know if you'd like me to break up this PR. I'd be happy to split these commits out if you don't want everything in this PR.

[claassistantio]

All committers have signed the CLA.

[michaelbabiy]

David, this looks awesome. Thanks!