docs(tigera-operator): Update values.yaml & the readme

[tom-ludwig]

Description

Update the documentation for the tigera operator helm chart.

• Update readme of the helm chart
  • Remove old kubeletVolumePluginPath and move it to installation.kubeletVolumePluginPath
  • Update URL of the installation spec
• Update values.yaml
  • Add URL to installationSpec
  • Add most important default values to allow the user to quickly adapt the values to their use case

When I start with a poc of a new operator, I'll usually try to deploy it to our poc landscape as soon as possible. For that I just copy the values.yaml and tweak them to my use case. I think these changes will make it easier and more clearer where to start.

Related issues/PRs

• closes #11479

Todos

• [x] Tests
• [x] Documentation
• [ ] Release note

Release Note

Improve tigera-operator helm chart default values.yaml so it is easier to discover available configuration options. 

Reminder for the reviewer

Make sure that this PR has the correct labels and milestone set.

Every PR needs one docs-* label.

• docs-pr-required: This change requires a change to the documentation that has not been completed yet.
• docs-completed: This change has all necessary documentation completed.
• docs-not-required: This change has no user-facing impact and requires no docs.

Every PR needs one release-note-* label.

• release-note-required: This PR has user-facing changes. Most PRs should have this label.
• release-note-not-required: This PR has no user-facing changes.

Other optional labels:

• cherry-pick-candidate: This PR should be cherry-picked to an earlier release. For bug fixes only.
• needs-operator-pr: This PR is related to install and requires a corresponding change to the operator.

[CLAassistant]

All committers have signed the CLA.

[tom-ludwig]

@caseydavenport I didn't think of that, good catch! I haven't been in the operator code, so I'll take your word for it 😅. Leaving them as comments sounds perfect and would already help me as a user.

[tom-ludwig]

@caseydavenport can you please take another look at this? Appreciate it!