Improved checklist for customizing a repo

[nedmsmith]

When going through the process of cloning a repo from the template I improved the checklist based on my experience.

Checklist for users of this template

• Create a new repository in https://github.com/organizations/TrustedComputingGroup/repositories/new
• In the Create a new repository dialog box

• Select "TrustedComputingGroup" in the Select an organization drop down
• Select "TrustedComputingGroup/specification-example" in the Repository template drop down
• Enter the name of your new repository in Repository name
• Select Private for most TCG documents
• Hit the Create repository button

• Navigate to the newly created repository then click on Settings:
• Add the correct GitHub team(s) to Collaborators
• Add TCGadmin to Admin
• Navigate to Branches:
• Add a branch protection rule on main

• Require a pull request before merging
• Required approvals > 0
• Do not allow bypassing the above settings
• (Optional) Require review from Code Owners (Requires setting up CODEOWNERS file)

• (Optional) rename spec.md and update all references in actions.yml
• Check for newer pandoc and
  markdown action versions
  for actions.yml
• Update the document title and type in the YAML front matter
• (Optional) Do an initial release to set baseline version (e.g., if migrating
  from an existing Word doc).
• (Optional) Review the guidance about release naming in the latest User's
  Guide from https://github.com/trustedcomputinggroup/pandoc.

I found it awkward for the checklist being burried inside of the spec.tcg template.
It would make more sense if the template had a README.md file with the checklist as people typically look at README files first.