[Document][Improvement] Add instructions on how to configure logging level for debugging purpose

[EricGao888]

Purpose of the pull request

• Add instructions on how to configure logging level for debugging purpose.

• We have already set root logging level to INFO, therefore, we do not need another filter to do so:
  

  dolphinscheduler/dolphinscheduler-standalone-server/src/main/resources/logback-spring.xml

  Lines 75 to 83 in e702bec

  	<root level="INFO">
  	<if condition="${DOCKER:-false}">
  	<then>
  	<appender-ref ref="STDOUT"/>
  	</then>
  	</if>
  	<appender-ref ref="STANDALONELOGFILE"/>
  	<appender-ref ref="TASKLOGFILE"/>
  	</root>

• This PR closes: [Doc][Contribute] Add examples about how to configure log level for a specific package in DS #12696

Brief change log

• Described above.

Verify this pull request

• Verified manually.

[codecov-commenter]

Codecov Report

Merging #12699 (1380c66) into dev (e702bec) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##                dev   #12699   +/-   ##
=========================================
  Coverage     39.14%   39.14%           
- Complexity     4207     4208    +1     
=========================================
  Files          1045     1045           
  Lines         39685    39685           
  Branches       4565     4561    -4     
=========================================
  Hits          15536    15536           
+ Misses        22384    22383    -1     
- Partials       1765     1766    +1     

Impacted Files	Coverage Δ
...pache/dolphinscheduler/common/utils/DateUtils.java	68.30% <0.00%> (-0.55%)	⬇️
...r/plugin/task/sqoop/parameter/SqoopParameters.java	52.38% <0.00%> (+1.19%)	⬆️

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[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
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[SbloodyS]

LGTM