✏️ Rewrite "optionnal" to "optional" (#1278)

Update the spelling of the word "optionnal" to "optional" in 4 places.

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **New Features**
	- Made the file type selection optional in the file upload feature.
- **Bug Fixes**
- Addressed issues with color mode synchronization, persistence, and
user reset behavior.
	- Improved caching and bundling of files.
- **Documentation**
- Corrected spelling errors and typos in various documentation files for
better clarity and accuracy.
- **Style**
	- Updated admin display labels for enhanced clarity.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: Baptiste Arnaud <baptiste.arnaud95@gmail.com>

apps/docs/contribute/guides/local-installation.mdx

@@ -44,7 +44,7 @@ icon: 'laptop'
 
    By default, you can easily authenticate in the builder using the "Github Sign In" button. For other options, check out the [Configuration guide](https://docs.typebot.io/self-hosting/configuration)
 
-6. (Optionnal) Start the landing page
+6. (Optional) Start the landing page
 
    Copy `apps/landing-page/.env.local.example` to `apps/landing-page/.env.local`
 
@@ -53,7 +53,7 @@ icon: 'laptop'
    pnpm dev
    ```
 
-7. (Optionnal) Start the docs
+7. (Optional) Start the docs
 
    ```sh
    cd apps/docs