Handle inline comments

[adammw]

What

Allows psych-comments gem to parse inline comments and round-trip them back to exported YAML

Example:

fruits: # don't add more than 5
- apples
- bananas
- tomatoes # requires some explanation

Why

Mostly because I didn't see that this had already been attempted in #2 😓 and was looking to use this feature in a custom linter/fixer, but the reformatting of inline comments was a deal-breaker.

Tasks

• Review problems with previous attempt to ensure same issues are not present here
• Support inline comments on first line of flow-style mapping/sequence

{ # an inline comment here is not supported
  foo: bar # here is
 } # as is here

• Fix duplicated inline comments on flow mapping/sequences