Doc: Readme updates to align with the new Red Hat template

[JulioPDX]

Change Summary

README at the root of the collection has been updated to conform with the new Red Hat collection template. Due to not being able to link to files outside of the Mkdocs docs_dir location, the old README at the root of the collection has been renamed to index.md. This is used as the homepage on the documentation site. The root README for the repository is only used for GitHub.

Proposed changes

Please see the change summary

How to test

No updates to main site docs.

Checklist

User Checklist

• N/A

Repository Checklist

• My code has been rebased from devel before I start
• I have read the CONTRIBUTING document.
• My change requires a change to the documentation and documentation have been updated accordingly.
• I have updated molecule CI testing accordingly. (check the box if not applicable)

[github-actions]

Review docs on Read the Docs

To test this pull request:

# Create virtual environment for this testing below the current directory
python -m venv test-avd-pr-4024
# Activate the virtual environment
source test-avd-pr-4024/bin/activate
# Install all requirements including PyAVD
pip install "pyavd[ansible] @ git+https://github.com/JulioPDX/ansible-avd.git@readme-updates#subdirectory=python-avd" --force
# Install Ansible collection
ansible-galaxy collection install git+https://github.com/JulioPDX/ansible-avd.git#/ansible_collections/arista/avd/,readme-updates --force
# Optional: Install AVD examples
cd test-avd-pr-4024
ansible-playbook arista.avd.install_examples

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.3% Duplication on New Code

See analysis details on SonarCloud

[carlbuchmann]

LGTM