Extract Dictionary Content to a Standalone Repository

- Implementation PR:

# Summary
We plan to extract the dictionary content (currently stored as `.mdx` files) from the main `jargonsdev/jargons.dev` repository and move it to a dedicated repository. This separation will allow us to use Astro’s new content layer feature to load dictionary content dynamically from a remote source, improving the maintainability and scalability of the project.

# Motivation
Currently, both the jargons.dev app source code and the dictionary content reside in the same repository. This setup limits the ability to manage and scale these components separately. By moving the dictionary content to its own repository, we can:
- Separate the content from the app code, enabling more focused contributions.
- Make it easier for contributors to update content without touching the app code.
- Leverage the Astro content layer to dynamically load content from a remote source, allowing for more flexibility.

# Goal
1. **Create a new repository** for dictionary content, for example, `jargonsdev/dictionary`.
2. **Extract all `.mdx` files** from the current `jargonsdev/jargons.dev` repository in the `content/dictionary` directory and move them to the new repository.
3. **Integrate Astro’s content layer** to fetch and load the dictionary content from the new remote repository into the app.
4. Update **contribution guidelines** to reflect the new structure, making it clear how to contribute to both the app and the dictionary content.
5. **Test and validate** the integration to ensure the dictionary content is properly loaded and the app functions as expected.

By achieving these goals, we will streamline the management of content and code, paving the way for more efficient collaboration and future scalability.

Start by reviewing the current content/dictionary directory and the app's Astro content-loading setup. Define the new dictionary repository structure, migrate the .mdx files, update contribution guidelines, and validate that remote content loads correctly and the app still functions as expected.

Written by the indexing model from the issue text.