Pipeline: Create and maintain release upgrade docs

[bobcatfish]

Expected Behavior

If a person had an older version of Tekton pipelines installed, e.g. 0.5.2, and they want to upgrade to a newer version such as 0.6.0, they should be able to look at some docs that explain to them how to make any needed updates between the two (e.g. backwards incompatible changes, and backwards incompatible change warnings).

Actual Behavior

Folks can see what exactly has changed in the release notes https://github.com/tektoncd/pipeline/releases but it still may not be clear what action they should take.

For example, for https://github.com/tektoncd/pipeline/releases/tag/v0.6.0 folks should be taking actions such as:

• Updating uses of affinity, etc. with podTemplate
• Keeping an eye out for errors resulting from accidentally including unknown fields
• etc.

(But with more detail than that!)

Additional Info

We should try to accumulate these docs as we go vs. making the person doing the release add them all at once. We may want to start keeping a running release notes doc in the repo and when we encounter backwards incompatible or soon to be incompatible changes, folks should update those docs.

[tekton-robot]

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Mark the issue as fresh with /remove-lifecycle stale.
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/lifecycle stale

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[bobcatfish]

I still think this is a good idea but maybe it makes sense to let it get auto closed if no one is able to engage?

[vdemeester]

Also, adding to this that, the operator would have code on this (aka upgrading from a version to a new one).

[bobcatfish]

Makes sense @vdemeester - that's even better!

[tekton-robot]

Stale issues rot after 30d of inactivity.
Mark the issue as fresh with /remove-lifecycle rotten.
Rotten issues close after an additional 30d of inactivity.
If this issue is safe to close now please do so with /close.

/lifecycle rotten

Send feedback to tektoncd/plumbing.

[vdemeester]

/remove-lifecycle rotten

[tekton-robot]

Issues go stale after 90d of inactivity.
Mark the issue as fresh with /remove-lifecycle stale with a justification.
Stale issues rot after an additional 30d of inactivity and eventually close.
If this issue is safe to close now please do so with /close with a justification.
If this issue should be exempted, mark the issue as frozen with /lifecycle frozen with a justification.

/lifecycle stale

Send feedback to tektoncd/plumbing.

[bobcatfish]

I think we could let this go rotten and close if we feel like the docs we provide in the release notes are enough?