Format README and partial fix for issue #2

(How much detail would you like to be in the pull request, vs what's in the actual commits? Because right now I'm just going to be conservative and include all of the commit content.)

### Commit One:
Improve README formatting

Specifically:
* Display keywords and filenames in monospace
* Link to documentation for `pallet.action.remote-file`
* Display possible `postgres-settings` keys in an unordered list


### Commit Two:
Partially fix issue #2