Auto-generate annotation docs

[rikatz]

What this PR does / why we need it:

To make it easier for users to determine what's the annotation risk, we can generate a secondary annotation page containing data read from the code.

This PR adds an util for it

[k8s-ci-robot]

This issue is currently awaiting triage.

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[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: rikatz

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• OWNERS [rikatz]

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[Gacko]

/cherry-pick release-1.10

[Gacko]

/cherry-pick release-1.11

[k8s-infra-cherrypick-robot]

@Gacko: #11820 failed to apply on top of branch "release-1.10":

Applying: Auto-generate annotation docs
.git/rebase-apply/patch:36: trailing whitespace.
        
.git/rebase-apply/patch:331: new blank line at EOF.
+
warning: 2 lines add whitespace errors.
Using index info to reconstruct a base tree...
M	internal/ingress/annotations/annotations.go
Falling back to patching base and 3-way merge...
Auto-merging internal/ingress/annotations/annotations.go
CONFLICT (content): Merge conflict in internal/ingress/annotations/annotations.go
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 Auto-generate annotation docs
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".

In response to this:

/cherry-pick release-1.10

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[k8s-infra-cherrypick-robot]

@Gacko: new pull request created: #11831

In response to this:

/cherry-pick release-1.11

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.