chore: Simplify search index generation

chore: Move component overview to @nuxt/content

Instead of relying on a custom implementation, we can simply move to @nuxt/content for our component overview

chore: Replace search indexing with simpler implementation

We currently have a custom implementation which creates a search index of our markdown files. Thanks to @nuxt/content this can be simplified.

We create a new module which ties two nuxt modules together:

• @nuxtjs/lunr-module which we use for our static search
• @nuxt/content which we use to load the markdown content files

@nuxt/content has an internal database and every time a document is inserted into that database, we insert a new document into our @nuxtjs/lunr-module search index