feat: timestamp document

[NguyenHoangSon96]

Closes #222 (comment)

Proposed Changes

_ More detail documents about timestamp for query and write functions

Checklist

• CHANGELOG.md updated
• Rebased/mergeable
• A test has been added if appropriate
• Tests pass
• Commit messages are conventional
• Sign CLA (if not already signed)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.05%. Comparing base (9008c68) to head (18f1b64).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #233   +/-   ##
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  Coverage   90.05%   90.05%           
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  Files          18       18           
  Lines        1036     1036           
  Branches      164      164           
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  Hits          933      933           
  Misses         40       40           
  Partials       63       63           

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[Copilot]

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (2)

src/main/java/com/influxdb/v3/client/InfluxDBClient.java:80

• [nitpick] Consider capitalizing 'Note:' for consistency with common JavaDoc style.

 * note: the timestamp passed will be converted to nanoseconds since the Unix epoch

CHANGELOG.md:6

• [nitpick] Consider revising the phrasing to 'More detailed documentation about timestamp handling for query and write functions' for improved clarity.

2. [#233](https://github.com/InfluxCommunity/influxdb3-java/pull/233): More detail documents about timestamp for query and write functions

[jansimonb]

LGTM