README and REST documentation formatting improvement

Small formatting improvements to the README and REST documentation.

For the README I've updated the bulk of it so that it wraps at 79 characters and also updated the formatting so that it reflects the way markdown actually renders the content.

For the REST template, I've made similar changes and rebuilt REST.md. There were some differences I noticed in the output for three of the examples, specifically:

* GET /v2/apps/{app_id}/tasks
* DELETE /v2/apps/{app_id}/tasks?host={host}&scale={true|false}
* GET /v1/endpoints

It appears this may just be a result of the template build process, but I thought I would point it out in case there is an issue here...