refactor: function naming change (is->check), code modularization

[tooooo1]

Summary

Implemented several codebase enhancements including renaming a key function for clarity, modularizing the codebase for better maintainability, and updating the demo to reflect these changes.

+Added jsdoc

future work: checkSupport func develop

Checks

Please check the following:

• I have written documents and tests, if needed.

[changeset-bot]

🦋 Changeset detected

Latest commit: ba5e72d

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@fepack/image	Patch

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[codecov]

Codecov Report

Merging #12 (ba5e72d) into main (c08a063) will not change coverage.
The diff coverage is 50.00%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #12   +/-   ##
=======================================
  Coverage   50.00%   50.00%           
=======================================
  Files           1        2    +1     
  Lines          12       12           
  Branches        2        2           
=======================================
  Hits            6        6           
  Misses          5        5           
  Partials        1        1           

Components	Coverage Δ
@fepack/image	50.00% <50.00%> (ø)