KAFKA-8416: Clarify two-step requirement for enabling Streams topology optimizations

[emmaeng700]

The existing docs mentioned both steps in a single dense sentence,
making it easy to miss that Properties must also be passed to
StreamsBuilder.build().

Added a numbered list and code example clearly showing both steps, with
an explicit warning that calling build() without Properties silently
skips optimizations even when the config is set.

Reviewers: Matthias J. Sax matthias@confluent.io

[mjsax]

Thanks for the PR @emmaeng700 -- what's your Jira account so we can assign the ticket to you?

Btw: It's recommended to first assign Jira tickets, so make sure no duplicate work is done.

[mjsax]

This PR is great improvement, but not sure if it already fully address the ticket? -- Did you check other parts of the docs, to see if there is any other place we should update? The Jira ticket also mentions to maybe also update JavaDocs?

[emmaeng700]

My Jira account is emmaeng700.

Good catch on the JavaDocs — I looked at StreamsBuilder.java and both build() and build(Properties) were missing the same clarity. I've updated them in this PR: build() now points users to build(Properties) and explains that optimizations won't apply without it, and build(Properties) now has the
full two-step requirement spelled out with the numbered list.

[emmaeng700]

Thanks @mjsax! I did a full pass over the docs and found one more gap: had no mention of the two-step requirement in its Javadoc or the config description string. Updated both in the latest commit.

Full list of places now covered:

• — expanded with numbered steps + code example
• Javadoc — cross-links to and explains why
• Javadoc — explains both required steps
• Javadoc — warns config alone is not enough
• config description string — same note

Let me know if there are other areas to cover.

[mjsax]

Thanks for the fix! Merged to trunk.