feat: add reusable workflows for consumption across repos

[Lstedmanfalls]

What is the Feature / Change Being Made?

The template-repo in this org housed Github Actions workflows that were duplicated across each repo. Instead of repeating the common workflows, including semver release, pr title validation, etc, this new repo houses centralized reusable workflows that can be called by other repos instead.

What is the Rationale in Relation to Best Practices?

This keeps code DRYer, allowing updates to common workflows in this centralized place instead of having to update each repo's workflow individually, can just update the version if / when needed.

How Has This Been Tested?

Tested each workflow, except semver-release, in this PR in the template-repo by pointing to this feature branch. For workflows typically run as cron jobs, I temporarily switched the trigger to on PR. Verified that all workflows are behaving as expected.

How Can the Community Use This?

Usage instructions are outlined in the README.

Links to Related Issues or Discussions

mindbuttergold/aws-multi-account#1 (comment) @BA-CalderonMorales brought up discussion on a previous PR in an org repo about reusability of workflows.

Contribution Reminders

Your PR needs:

• At least 5 thumbs up from members of the community to be approved / merged
• Final review / approval from at least one maintainer
• Clear, complete, and fully usable code for real-world systems
• No placeholder, unfinished, or copied code with incompatible licensing
• No redundant comments or unrelated artifacts
• The PR title to follow conventional commit standards

Refer the CONTRIBUTING guidelines and CODE_OF_CONDUCT for more information.

[BA-CalderonMorales]

I'll try to find a repo to leverage these @Lstedmanfalls - thank you for revisiting this for the community.

You're an inspiration. 🚀

Hope folks can chime in.

[github-actions]

🎉 This PR is included in version 1.0.0 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀