Upload the docs automatically at each release with github actions and add tests for them in the CI

[gabrieldemarmiesse]

Feature Description

See the title

Reason

• This would allow contributors to make pull requests to change how to generate the docs.
• Currently the docs online are referring to the last commit in the master branch. The docs should explain how to use the latest version on PyPI.

Solution

• The docs should be pushed at each release. See https://github.com/keras-team/autokeras/blob/master/.github/workflows/publish.yml
• To avoid pushing untested changes to the docs generation, we should build the docs in the CI at each PR, but we shouldn't publish them. It should be done there: https://github.com/keras-team/autokeras/blob/master/.github/workflows/tests.yml

Alternative Solutions

Pushing at each new commit on master is nice for devs because they have quick feedback, but it's not great for users. Maybe we should have a separate website for the latest docs?

Additional Context

It seems the latests docs were not build with the latest version of keras autodoc, because the aliases are not used in the type hints.

[haifeng-jin]

That is a good point!

We can use git workflow for docs, to enable the hotfixes to the docs for the released version.
We don't need to release the bleeding edge docs, if the user really would like to read, they can generate the docs locally.
So the website should be updated automatically with each release and manually when there is a hotfix to the docs.

Thanks.