[improve][doc] ProducerBuilder.java

[mendonk]

Motivation

Improve the comments in ProducerBuilder.java for clarity and cleanliness.
These can be the first documentation devs see in an IDE, so they should inspire more confidence in users.

Modifications

Cleaned up the comments in the ProducerBuilder.java file.

Verifying this change

• Make sure that the change passes the CI checks.
  [improve][doc] ProducerBuilder.java mendonk/pulsar#1

(Please pick either of the following options)

This change is a trivial rework / code cleanup without any test coverage.

(or)

This change is already covered by existing tests, such as (please describe tests).

(or)

This change added tests and can be verified as follows:

(example:)

• Added integration tests for end-to-end deployment with large payloads (10MB)
• Extended integration test for recovery after broker failure

Does this pull request potentially affect one of the following parts:

If the box was checked, please highlight the changes

• Dependencies (add or upgrade a dependency)
• The public API
• The schema
• The default values of configurations
• The threading model
• The binary protocol
• The REST endpoints
• The admin CLI options
• Anything that affects deployment

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete

[tisonkun]

Thanks for taking care of the javadoc!

Comments inline.

[tisonkun]

Thanks for your contribution @mendonk! LGTM.

[codecov-commenter]

Codecov Report

Merging #18809 (0ccac3d) into master (99e26f5) will decrease coverage by 3.16%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master   #18809      +/-   ##
============================================
- Coverage     44.79%   41.62%   -3.17%     
+ Complexity    10026     2406    -7620     
============================================
  Files           703      235     -468     
  Lines         68808    16677   -52131     
  Branches       7375     1819    -5556     
============================================
- Hits          30822     6942   -23880     
+ Misses        34378     8977   -25401     
+ Partials       3608      758    -2850     

Flag	Coverage Δ
unittests	41.62% <ø> (-3.17%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...he/pulsar/client/impl/MultiTopicsConsumerImpl.java	22.78% <0.00%> (-0.20%)	⬇️
...va/org/apache/pulsar/client/impl/ConsumerImpl.java	15.09% <0.00%> (-0.04%)	⬇️
...ker/stats/prometheus/AggregatedNamespaceStats.java
...org/apache/pulsar/broker/service/Subscription.java
...org/apache/pulsar/PulsarInitialNamespaceSetup.java
...n/java/org/apache/pulsar/compaction/Compactor.java
.../apache/pulsar/broker/loadbalance/LoadManager.java
.../org/apache/bookkeeper/mledger/impl/EntryImpl.java
.../prometheus/metrics/DataSketchesSummaryLogger.java
...ger/offload/jcloud/impl/BufferedOffloadStream.java
... and 462 more

[tisonkun]

Merging...