Misc doc updates

Starting to do a complete review of all the Relish docs. I often find myself using these daily or trying to point users to them. I've created a list of things that need updating / adding. This is the first pass on the core docs fixing mostly minor issues.

- [ ] Capitalize the first word of scenarios
- [ ] Use back ticks for `inline code` and `options` consistently
- [ ] Minor grammatical issues
- [ ] Fix whitespace wraps as viewed on Relish (wrap to a general 80 cols)

**DO NOT MERGE YET**