Clarification of commas a bit more.

* Don't add a space when adding a newline... this just makes things messy if an editor doesn't support `.editorconfig`
* Separate out Comma Separator from Comma Operator
* Remove the `var statements` from Comma Separator *(plus it's an operator btw)* because we don't currently allow that under [Variable Declarations](https://github.com/OpenUserJs/OpenUserJS.org/blob/master/STYLEGUIDE.md#variable-declarations) and can confuse contributors.

Applies to #19

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Auto-merge
> in the control part of `for` statements.

Huh? Perhaps a dumb question, but when do you use commas in a `for` statement?