HLA-1415: Remove unused alignment parameter files and update documentation

[s-goldman]

Resolves HLA-1415

This PR documents the alignment configuration files for pipeline products, SVMs and MVMs.

1. I've added documentation to the HAP-parameters page with a table showing the rules for the configuration files. I've attached a rendering of the RTD page for ease of review. The table is cut off in the screenshot, but one can slide over on the actual page.
2. I noticed that in several cases, we specify a "any_4" file, but it is identical to the "any_2" file. In this case, i've removed the "any_4" file and updated the config_utils.py file to point to the "any_2" in the case of 2, 3, 4, or 5 exposures. This was already done for some of the detectors, so I'm doing it for all the relevant cases for consistency.
3. As the MVM's either use "any_1" for 1 exposure or "any_2" for all other cases, I've removed the "any_4" and "any_6" parameter files as they are not used.

I've also added a helpful link from the SVM-processing section that touches on these filenames, to this documentation.

Checklist for maintainers

• [x] added entry in CHANGELOG.rst within the relevant release section
• [x] updated or added relevant tests
• [x] updated relevant documentation
• [x] added relevant label(s)

Regression test passing: Link