Update README.md, INSTALL, CONTRIBUTING.md and test/README.md

These files should reflect the overall test state of aurweb prove tests and its new fastapi python tests. Include details about what exactly needs to be done when testing and easy ways to resolve issues you may run into. We should be very elaborate here, as this should be the main documentation for the product.

added To Do label

assigned to @kevr

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added Doing label and removed To Do label

changed title from Update README.md and CONTRIBUTING.md to Update README.md, INSTALL, CONTRIBUTING.md and test/README.md

added Done label and removed Doing label

closed