feat: add require-form-method rule

[yeonjuan]

ref #54

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.32%. Comparing base (53af02b) to head (84f765f).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #254      +/-   ##
==========================================
+ Coverage   98.29%   98.32%   +0.02%     
==========================================
  Files          61       62       +1     
  Lines        1704     1729      +25     
  Branches      462      469       +7     
==========================================
+ Hits         1675     1700      +25     
  Misses         29       29              

Flag	Coverage Δ
unittest	98.32% <100.00%> (+0.02%)	⬆️

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Files with missing lines	Coverage Δ
packages/eslint-plugin/lib/rules/index.js	100.00% <100.00%> (ø)
...ges/eslint-plugin/lib/rules/require-form-method.js	100.00% <100.00%> (ø)