doc: Remove references to removed hugegraph-style.xml

[bitflicker64]

Purpose of the PR

close #2948

hugegraph-style.xml has been removed from the repository, but multiple documentation files still referenced it. This PR removes those stale references and updates the documentation to use .editorconfig and the existing Checkstyle configuration.

Main Changes

• Removed references to deleted hugegraph-style.xml
• Updated documentation to reference .editorconfig
• No functional or build changes

Verifying these changes

• Trivial rework / documentation cleanup. (No Need)

Does this PR potentially affect the following parts?

• Nope

Documentation Status

• Doc - Done

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 33.97%. Comparing base (6ffdd9c) to head (c7e6cee).
⚠️ Report is 2 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #2949      +/-   ##
============================================
- Coverage     35.55%   33.97%   -1.58%     
- Complexity      333      500     +167     
============================================
  Files           801      812      +11     
  Lines         67537    68688    +1151     
  Branches       8780     8977     +197     
============================================
- Hits          24013    23340     -673     
- Misses        40967    42863    +1896     
+ Partials       2557     2485      -72     

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