Add note to README about double quoted/plain YAML string escape characters

[derekjobst]

Due to the way yaml is decoded, \ characters must be escaped when used in strings with double quotes, but should not be escaped in plain style strings without quotes.

[bluekeyes]

While including the note here works, many other predicates also use regular expressions. Maybe it would be beneficial to instead add a section like Notes on YAML Syntax to the README as a sub-heading of the policy.yml Specification section?

That would give space to be more expansive and add other notes in the future. For example, I just checked and single quoted strings are also valid and don't need escaping.

[derekjobst]

That's a great idea. I'll add the section now. I'd be worried users might miss it when looking up a single regex based rule in the examples — what do you think of adding a note to comment_patterns and changed_files paths that repeat the difference and reference this new section?

[bluekeyes]

The inline comment format isn't great for adding lots of information about each property and I'd be worried about duplication, but I think a line similar to See "Notes on YAML Syntax" for tips to correctly escape regular expressions above each relevant property would be fine.

[bluekeyes]

I'd place this after the sample YAML block and before the Remote Policy Configuration section. Right now, the previous text says "Consider the following example" but then this section appears before the example.

[derekjobst]

Oops, good catch