Vandivier/ladderly-3

AI Summary: This issue requests the implementation of KaTeX support, as the current setup is failing to render mathematical expressions, likely for content similar to the linked blog post. The proposed solution involves installing and integrating `remark-math`, `rehype-katex`, and `katex`.

AI Summary: The user is requesting a multi-select feature for filtering LeetCode patterns (e.g., Array, String, Hash Table). The provided image illustrates the desired user interface where multiple pattern checkboxes can be selected simultaneously to filter problems.

AI Summary: Implement a GitHub Action that warns on pull requests older than one month and closes them after an additional week of inactivity. This requires configuring the action to interact with the Ladderly.io repository and potentially integrating with existing CI/CD pipelines.