chore: Export generate

[zombieJ]

Cascader 可以被看做是特殊的 TreeSelect，拆出 OptionList 用于额外配置。

Cascader > TreeSelect > Select

[vercel]

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🔍 Inspect: https://vercel.com/react-component/tree-select/GZvYvDfztwi15u7Ch9yE59TDwKJE
✅ Preview: https://tree-select-git-generate-react-component.vercel.app

[codecov]

Codecov Report

Merging #365 (f0fb2db) into master (9e237bd) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master      #365   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           11        12    +1     
  Lines          520       526    +6     
  Branches       152       144    -8     
=========================================
+ Hits           520       526    +6     

Impacted Files	Coverage Δ
src/Context.tsx	100.00% <ø> (ø)
src/OptionList.tsx	100.00% <ø> (ø)
src/TreeSelect.tsx	100.00% <100.00%> (ø)
src/generate.tsx	100.00% <100.00%> (ø)

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