pre-commit, dependabot and CI workflows

[CasperWA]

Closes #3

Adds:

• pre-commit As a versioned dependency in a requirements.txt file. Hooks for:
  • Check JSON
  • Check YAML
  • Fix end-of-file
  • Remove trailing whitespace
  • Run markdownlint, fixing files in-place, where possible.
  • Run ci-cd's Update Landing Page (index.md) for Documentation hook.
• Dependabot Update dependencies (currently only pre-commit) in requirements.txt. Update GitHub Actions used in CI workflows.
• GitHub Actions CI workflows
  • CI - Activate auto-merging for automated PRs Runs when a PR is opened by Dependabot or pre-commit.ci that targets the main branch. NOTE: Using a "new" pathway (GitHub CLI) to activate auto-merging, which might fail - keep tabs on this when a Dependabot PR is opened.
• pre-commit.ci Added through special configuration in the .pre-commit-config.yaml file. It does two things:
  • Run pre-commit for all PRs as a status check.
  • Automatically open PRs to update the pre-commit hooks.

Also:

• Adds a markdownlint configuration file. This sets the line length to 88 characters for code blocks and headers. Otherwise it sets the line length to an arbitrarily large value to ensure we can manually implement the "1-line-per-sentence" rule.
• Fix JSON files and markdown files according to outcome of running pre-commit.

Potentially missing from this PR:

• [x] Write installation and usage instructions in README or a new documentation file.

[CasperWA]

@sygout Is this fine as is or should I spend some extra time writing out the installation and usage instructions as I suggested in the original post? Otherwise, I am open to just making this ready for review and creating a new issue to follow-up the creation of the installation and usage instructions at a later point.

[sygout]

it looks fine. Let's find out first how it should be used and then write the documentation.

I wonder if the text you wrote in your pull request should be put in a documentation file. It could be helpful to have written down (for humans) what the pipelines are doing, or what is configure in plain text. I am thinking about educating new developer.