docs(community): remove Grammarly extension recommendation (vercel#66195

)

## Why?

The Grammarly extension is no longer active.

- https://github.com/znck/grammarly
- Closes vercel#66194

docs/05-community/01-contribution-guide.mdx

@@ -53,7 +53,6 @@ Next, open the command palette again, and search for `Markdown: Preview File` or
 We also recommend the following extensions for VSCode users:
 
 - [MDX](https://marketplace.visualstudio.com/items?itemName=unifiedjs.vscode-mdx): Intellisense and syntax highlighting for MDX.
-- [Grammarly](https://marketplace.visualstudio.com/items?itemName=znck.grammarly): Grammar and spell checker.
 - [Prettier](https://marketplace.visualstudio.com/items?itemName=esbenp.prettier-vscode): Format MDX files on save.
 
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