Implemented: License and Documentation Improvements

Hello,

In this pull request we expand and refine the documentation of the nxc_social_networks extension.

- Expand README.md documentation
- Add LICENSE documentation
- Expand COPYRIGHT and CREDITS documentation
- Add extension TODO and FAQ documentation stubs

We think these documentation improvements help make the extension more accessible to all users.

The license documentation is required by the terms of the license.

The readme documentation makes the extension simpler to install and use.

The copyright, credits, todo and faq documentation makes the extension easier to use and understand.

Please let us know what you think of these improvements!

Cheers,
Brookins Consulting