Add extraInitContainer option

[pratiyushpushkar05]

Small change .
It allows users to add initContainer of their choice in deployment .
Issue : #286

[pierluigilenoci]

The PR is correct, but a test case needs to be added here to verify during the pipeline that the chart works with this feature.

Ref:

• https://github.com/oauth2-proxy/manifests/blob/main/.github/workflows/lint-test.yaml#L46
• https://github.com/helm/chart-testing

[tuunit]

Sorry but I had to fix the markdown table formatting. It has been broken since the introduction of the description for option initContainers.waitForRedis.kubectlVersion

[tuunit]

@pratiyushpushkar05 why did you revert the changes I made to the README.md?

[pratiyushpushkar05]

@pratiyushpushkar05 why did you revert the changes I made to the README.md?

@tuunit Must have been missed out . Didnot revert on purpose .I can see your commit on browser but not in git log locally . Sorry for inconvenience .
May be related to git force push .

[tuunit]

@pratiyushpushkar05 why did you revert the changes I made to the README.md?

@tuunit Must have been missed out . Didnot revert on purpose .I can see your commit on browser but not in git log locally . Sorry for inconvenience . May be related to git force push .

I already made all the necessary changes to the PR yesterday...