Dev Support/Fix Make-docs-to-webpage Worfklow

[ThorntonMatthew]

Description

The Make-docs-to-webpage workflow has been updated to include a requisite Redis service and to resolve some deprecation warnings. Some new polymorphic associations have also been documented in the code in order for them to be able to be represented in our generated docs.

Acceptance Criteria

• The Make-docs-to-webpage workflow runs successfully
  • The workflow is able to push changes to web page files to the main-gh-pages branch
• The results of the workflows can be observed at https://department-of-veterans-affairs.github.io/caseflow/

Testing Plan

1. Review the last run of the Make-docs-to-webpage workflow (Link)
2. Review that the "Build and deploy to GH Pages" workflow is able to run successfully (Link)
3. See that the GitHub Pages site has been updated appropriately (ex: on the Caseflow Postgres DB Schema page).

[codeclimate]

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[ThorntonMatthew]

I ran a linter on this file and it fixed some inconsistencies with the whitespace.