markdown, html, plugin-scan requirements

What's Changed

• Remove commitlint, because it now runs on PR titles only by @spetrosi in #128
• ci: manually install python 2.7 by @richm in #130
• container improvements by @richm in #131
• ansible-lint - use creator-ee v0.19.0 by @richm in #132
• Make markdownlint consistent with our GH workflows, add convert_readme by @spetrosi in #133
• Run markdownlint on all md files, ignore vendor for metrics, remove badges when converting to HTML by @spetrosi in #134
• add --cleanup-yml to provide cleanup playbooks by @richm in #136
• In woke config ignore .README.html by @spetrosi in #138
• add Troubleshooting help by @richm in #140
• plugin-scan - use explicit collection requirements by @richm in #141
• bump version to 3.1.0 by @richm in #142

Full Changelog: 3.0.0...3.1.0