docs: use consistent tsconfig for both in docs and bun init

[risu729]

What does this PR do?

Follow up of #8654

Fixes inconsistent tsconfig comments in docs vs in bun init, except for the stricter flags.

For the stricter flags, I decided to include them also in bun init but disable them by default.
This inconsistency is clarified in the docs as follows.

If you run bun init in a new directory, this tsconfig.json will be generated for you. (The stricter flags are disabled by default.)

• Documentation or TypeScript types (it's okay to leave the rest blank in this case)
• Code changes

How did you verify your code works?

[Electroid]

Thanks!