Document pipeline types

[sxa]

Please describe what you want to be able to do that isn't documented and/or what you'd like to see in the documentation

We now have a large number of build types executed through pipelines:

• Nightly
• EA triggered builds
• Release builds
• Evaluation builds
• Weekend runs
• (Forthcoming) Trestle pipelines

Given the expansion of the different types we should have clear documentation on:

• what each of those are for
• what testing is done on them
• whether they are published (and whether the artifacts are renamed during the publish step)
• the scheduling/triggering
• where to find the jobs
• how/when they are regenerated by automation

I would suggest this might be in a table in the README.md or FAQ.md in this repository but open to other suggestions. This will help people understand what we're doing and when we're doing it.

Related:

• Update weekly test list #857
• Relax permissions on non-release pipeline jobs #865
• SBoM nightly artifact data names do not align with the published ones temurin-build#3600

[sxa]

Related (dup?) of #586