Minor fixes

* Include newlines after section heads
* Improve explanation of example at beginning
* Consistently end bulleted list (period)
* Consistently end bulleted lists (no period)
* Consistently place translation/license/contributing at the end of each section
* Consistently mark up **Platforms** / **OS**s
* Consistently mark up `protocol:`
* Consistently refrain from having a `:` or `-` at the beginning of each line