chore: Convert into TS

[zombieJ]

Use Typescript for new life cycle method preparing.

[vercel]

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[codecov]

Codecov Report

Merging #289 into master will increase coverage by 0.01%.
The diff coverage is 99.25%.

@@            Coverage Diff             @@
##           master     #289      +/-   ##
==========================================
+ Coverage   95.03%   95.05%   +0.01%     
==========================================
  Files          10       10              
  Lines         786      788       +2     
  Branches      230      230              
==========================================
+ Hits          747      749       +2     
  Misses         39       39

Impacted Files	Coverage Δ
src/placements.ts	100% <ø> (ø)
src/MenuItem.tsx	98.78% <100%> (ø)
src/MenuItemGroup.tsx	100% <100%> (ø)
src/SubPopupMenu.tsx	96.31% <100%> (ø)
src/SubMenu.tsx	97.95% <100%> (ø)
src/util.ts	95.45% <100%> (ø)
src/Menu.tsx	97.61% <100%> (ø)
src/Divider.tsx	100% <100%> (ø)
src/DOMWrap.tsx	85.18% <97.5%> (ø)

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