Update a couple inconsistent commented outputs

Updates `#=>` to `# =>`.

Reasons why `# =>` is preferred:
- used in TRPL and pickaxe
- this guide itself recommends using one space after the leading `#`
Merge pull request #337 from bruno-/fix_commented_output

Update a couple inconsistent commented outputs
[Fix #319] Add anchors to rule bullets

This adds subtle and nonugly link markup to every bulleted rule for ease
of deeplinking.
Merge pull request #338 from rapid7/add-anchors

Add anchors to bullets
Rejustify README.md to 80 columns
Merge pull request #339 from rapid7/justify-to-80-columns

Rejustify README.md to 80 columns