Search or filtering of menu items

[andrew-codes]

The old docs site had a way to filter menu items. This made it easy to locate components that users already had in mind. We could either; filter the menu based on matching search criteria to menu item value OR provide a deeper search on more than simply the component name (description, page contents, page frontmatter such as keywords or see also, etc.).

We should at the very least be able to filter the menu by matching menu item values.