Update ScaledJob scaling strategy section

[chinery]

Rewrite of the scaling strategy section of the ScaledJob spec, based on this issue and discussion on the community Zoom call.

Summary of changes:

• add an explanation for why a scaling strategy is required in the first place
• try to point out that default should work for most users (hopefully meaning they don't need to read this section at all!)
• tweak some language to increase clarity (e.g. "number of jobs to create" rather than "the number of the scale")
• update the eager section to reflect the actual behaviour (as discussed in the issue linked above)

With this PR, the documentation should correctly match the behaviour of KEDA 2.16, i.e. it does not include any of the minor changes I'm planning to make to the scaling strategy code, for which I'll make a separate docs PR (I've been busier than expected!).

Checklist

• [✓] Commits are signed with Developer Certificate of Origin (DCO)

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[chinery]

Excellent, sorry for the delay, could you please also update the file in 2.18 (upcoming) version?

https://github.com/kedacore/keda-docs/tree/main/content/docs/2.18

Hi @zroubalik, so sorry for an even longer delay on my part (and for a simple request!). Have just updated the file in 2.18 too.

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This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 7 days if no further activity occurs. Thank you for your contributions.

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This issue has been automatically closed due to inactivity.