add built documentation ZIP file artifact upload to docs workflow

[prjemian]

• close Upload built documentation as artifact #281

[prjemian]

GHA suggests:

docs (3.9)
This action is deprecated and no longer maintained. Please use mamba-org/setup-micromamba instead. See https://github.com/mamba-org/provision-with-micromamba#migration-to-setup-micromamba for a migration guide.

[prjemian]

@mrakitin Ready for review.

[prjemian]

Great idea! This works easily. NeXus will benefit, too.

[mrakitin]

Looks great! It's now easy to check the docs.

The only issue with the workflow can be that it may not pull enough commits/tags to version the docs properly. We can probably set those to non-default values (from https://github.com/actions/checkout):

    # Number of commits to fetch. 0 indicates all history for all branches and tags.
    # Default: 1
    fetch-depth: ''

    # Whether to fetch tags, even if fetch-depth > 0.
    # Default: false
    fetch-tags: ''

[prjemian]

Solves the problem with the wrong version posted in the web documentation! Thanks!