Migrate and update style guide wiki

[hey-august]

Wiki is old and should be moved up in the hierarchy and renamed.

https://developer.signalwire.com/freeswitch/FreeSWITCH-Explained/Community/Contributing-Documentation/Confluence-Wiki-Standards-and-Guidelines_1049056/

• Delete anything that's Confluence-specific
• Rename "Style Guide"

[MostlyDifferent]

Working on this.

[hey-august]

@MostlyDifferent thank you! Let me know if you hit any roadblocks. :)

[MostlyDifferent]

Just sent a pull request. Can probably use more work, but I think it's a workable first pass.