Make sure all error codes are documented

[JukkaL]

Sometimes an error code is not documented, which makes it harder for users to figure out why mypy geneated an error. Check if all error codes defined in mypy.errorcodes are mentioned in the documentation (docs/source/error_code_list*.rst) and add documentation for undocumented error codes.

[ThanhChinhBK]

can I handle this issue?

[JukkaL]

@ThanhChinhBK Sure! There's no need to sign up to work on particular issues -- you can just start working.

[ThanhChinhBK]

@JukkaL I created a PR for this issue, could you add reviewer for it

[Alex-Wengg]

@ThanhChinhBK I could help review it for you but there's merge conflict issue atm

[Mikil03]

Is this issue still open? I would like to contribute.

[BearNSteen]

I can handle this, it looks like it still needs to be done. Predicting I'll have it done in a couple of days.

[BearNSteen]

It looks like all of the error code documentation has been added, although the missing ones are located in error_code_list2.rst. I have gone through the list of error codes and confirmed all of them are documented between the two separate error code lists. If there are no further codes outside of mypy.errorcodes, this can be closed.

[Bellkross]

It looks like all of the error code documentation has been added, although the missing ones are located in error_code_list2.rst. I have gone through the list of error codes and confirmed all of them are documented between the two separate error code lists. If there are no further codes outside of mypy.errorcodes, this can be closed.

Should this be closed? As per above