[Suggestion]: Add some elaboration to the docs for TypeScript DOM events and Pure Functions

Summary

The Section on DOM events in the page Using TypeScript, mentions extracting functions, this can be elaborated further to include the case where we do get the types i.e. inline methods.

The section on Pure Functions contain a example of Teacups and guests, the global let guests variable should be incremented by 1, but is incremented by 2. Since, React is running in StrictMode for development, this might be confusing for newbies. Found here: https://react.dev/learn/keeping-components-pure#side-effects-unintended-consequences
Edit: The deep dive for this chapter contains the explanation.

Page

https://react.dev/learn/keeping-components-pure

Details

Add another small example where it shows that we do get types when using inline methods, to make it more clear.

Either turn off Strict mode for this example OR explain why we are getting 2, 4, 6 instead of the expected 1, 2, 3 because of React.StrictMode.

リンク先の keeping-components-pure ページと Using TypeScript セクションを開き、関数の抽出に関する DOM イベントの説明を見つけてください。イベントの型が推論されることを示す、小さなインラインメソッドの例を追加し、初めての人にも説明が明確か確認してください。