Docs: Default value for `useDefineForClassFields` is misleading / wrong

[MartinJohns]

Page URL:
https://www.typescriptlang.org/tsconfig/#useDefineForClassFields
https://www.typescriptlang.org/docs/handbook/compiler-options.html

Issue:
On both sites the default value is shown as false, when it actually depends on the target version.

Recommended Fix:
Add the same documentation that is/will be added as part of microsoft/TypeScript#45503.

[orta]

This should happen as a part of upgrading the TS site to 4.4 release when it comes out 👍🏻

[orta]

This is in with the 4.4 update 👍🏻