CI: update docs & tidy workflow

[casperdcl]

Describe your changes

• fix/update CI workflow readme links (e.g. paskino/conda-package-publish-action -> TomographicImaging/conda-package-publish-action)
• tidy/update CI workflow
  • merge docs build & publish jobs
  • remove repetition in names (e.g. conda_build_and_docs/conda_build -> build/conda)
  • bump conda-incubator/setup-miniconda@v2 -> v3 (underlying nodejs version update)

Describe any testing you have performed

Link relevant issues

Checklist when you are ready to request a review

• I have performed a self-review of my code
• I have added docstrings in line with the guidance in the developer guide
• I have implemented unit tests that cover any new or modified functionality
• CHANGELOG.md has been updated with any functionality change
• Request review from all relevant developers
• Change pull request label to 'Waiting for review'

Contribution Notes

Please read and adhere to the developer guide and local patterns and conventions.

• The content of this Pull Request (the Contribution) is intentionally submitted for inclusion in CIL (the Work) under the terms and conditions of the Apache-2.0 License.
• I confirm that the contribution does not violate any intellectual property rights of third parties