Ignore directives that are commented out

[BenLloydPearson]

Is your feature request related to a problem? Please describe.
If you comment out a directive inside an if: statement, that directive will still be run. Any directive lines that are preceded by a # should probably be ignored.

Describe the solution you'd like
Any configuration file lines that start with a # should be ignored.

Describe alternatives you've considered
You need to move the line to a place where it won't be run or delete it entirely.

Additional context
Reported here: #317 (comment)

[BenLloydPearson]

@PavelLinearB Related to this, I discovered that all items inside {{ }} will be treated as templates when they are inside comments. I suspect this may be a nunjucks behavior.

[BenLloydPearson]

The Jjinja docs indicate that comments should be structured like this {# comment #}. We'll need to investigate if this works in gitStream.