perf(update): incremental update tags on single file save

[linrongbin16]

successor of #8 .

[codecov]

Codecov Report

Attention: 39 lines in your changes are missing coverage. Please review.

Comparison is base (14dad2f) 69.58% compared to head (f66b3d2) 62.15%.

❗ Current head f66b3d2 differs from pull request most recent head 6a4376b. Consider uploading reports for the commit 6a4376b to get more accurate results

Files	Patch %	Lines
lua/gentags/ctags.lua	13.33%	39 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #11      +/-   ##
==========================================
- Coverage   69.58%   62.15%   -7.43%     
==========================================
  Files           5        5              
  Lines         263      288      +25     
==========================================
- Hits          183      179       -4     
- Misses         80      109      +29     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.