Several typo correction in doc files

[shail-mehta]

Description

I have reviewed Documentations & found several typo corrections in docs/contributors/folder-structure.md & docs/reference-guides/slotfills/README.md files.

1. targetted it should be targeted
2. developpers it should be developers
3. programatically it should be programmatically

Step-by-step reproduction instructions

1. Go to docs/contributors/folder-structure.md & docs/reference-guides/slotfills/README.md files
2. you will able to see the issue

Screenshots, screen recording, code snippet

No response

Environment info

No response

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes