Deploy documentation to Github Pages

[IvanIsCoding]

Related to #1035

Deploys the documentation to www.rustworkx.org via Github Pages. It:

• Builds the stable version on release and puts it at root; other stable versions and dev are copied
• Builds the latest version and puts in dev/ for each commit
• Ensures there is only one job running via the concurrency group

[coveralls]

Pull Request Test Coverage Report for Build 7449191322

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 95.872%

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Totals
Change from base Build 7449140407:	0.0%
Covered Lines:	15816
Relevant Lines:	16497

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💛 - Coveralls

[IvanIsCoding]

@mtreinish I addressed the comments, it should have the latest stable version at the root now