initial inclusion of frigate chart

[billimek]

This should add the frigate helm chart. Some updates to the readme are still necessary before a merge.

Closes https://github.com/blakeblackshear/frigate/issues/156

Important notes:

• The chart major version was bumped to help differentiate this chart from the parent https://github.com/k8s-at-home/charts/tree/master/charts/frigate repo
• The charts/frigate/ci/ci-values.yaml uses a public mqtt server and forces a CPU detector in order to facilitate successful test installation of the chart within an action
• The chart was updated to reflect changes in https://github.com/k8s-at-home/charts/pull/510 to support frigate v0.8.0
• The example frigate config in values.yaml is very sparse with a reference to the frigate configuration documentation for additional configuration options

[billimek]

@blakeblackshear this should be ready for your review and merge. It will be necessary to have a gh-pages branch for the release automation to properly work.