[FR]: doc: Custom Python interpreter needs to have pip installed

[georgevreilly]

What is the current behavior?

No response

Describe the feature

We build a custom Python interpreter into an artifact, which is downloaded at build time. To get rules_py to work, I had to update our interpreter build script to run bin/python -m ensurepip so that the pip package was installed at lib/python3.8/site-packages in the tarball. Otherwise, the rules_py virtualenv stuff fails miserably.

Please document any assumptions about the Python interpreter.

[alexeagle]

#33 suggests that we could drop the dependency on pip being supplied with the interpreter. But for 1.0 I think we'll just document this as being required as you suggest.

[mattem]

Will be resolved by #233