chore: add additional ignore file highlights (helix-editor#8220)

* chore: add additional ignore file highlights

Various files use the same syntax highlighting as `.gitignore` and
similarly tell different tools what files/folders to ignore. Update the
languages file so that other ignore type files use the same highlighting
as gitignore. The files added are:

- `.ignore`
- `.prettierignore`
- `.eslintignore`
- `.npmignore`

* chore: add highlighting for codeowners files

Add `CODEOWNERS` as an additional file type for `git-ignore` in the
language file. `CODEOWNERS`'s grammar is close enough to that of
`.gitignore`, this can be used to avoid making a new grammar
specifically for `CODEOWNERS` files.

languages.toml

@@ -1380,7 +1380,7 @@ source = { git = "https://github.com/mtoohey31/tree-sitter-gitattributes", rev =
 name = "git-ignore"
 scope = "source.gitignore"
 roots = []
-file-types = [".gitignore", ".gitignore_global"]
+file-types = [".gitignore", ".gitignore_global", ".ignore", ".prettierignore", ".eslintignore", ".npmignore", "CODEOWNERS"]
 injection-regex = "git-ignore"
 comment-token = "#"
 grammar = "gitignore"