Fixes a batch of grammatical mistakes found across the `docs/` folder:
typos/misspellings, subject-verb agreement errors, missing and
duplicated words, article errors (`a`/`an`), wrong word forms, and
punctuation issues (doubled periods, unclosed parentheses).

Scope is limited to prose in `docs/src/**`; no behavior, settings, or
code changes. 33 files updated, 49 lines changed.

Representative fixes:

- `globs.md`: "features varies" -> "features"; "platforms libc" ->
"platform's libc".
- `installation.md`: "the follow macOS releases" -> "the following macOS
releases".
- `key-bindings.md`: "command pallets" -> "command palette's".
- `linux.md`: capitalization after a period; "able to the environment
variable" -> "able to set the environment variable"; "These feature also
requires" -> "This feature also requires".
- `multibuffers.md`: "Window/Linux" -> "Windows/Linux"; added a missing
closing parenthesis.
- `reference/all-settings.md`: several agreement/article/missing-word
fixes plus an unclosed parenthesis.
- `languages/*`: "partent" -> "parent", "complimentary" ->
"complementary", "setup" -> "set up", "is enabled" -> "are enabled", and
similar.

Release Notes:

- N/A