Add resources index page

Created by: katjuell

Adds a resources index page and closes #5234

To Test

• Visit /resources and check that links work and card component looks correct.

Created by: katjuell

@elzannewentzel @bretthayes I'm marking this as a draft because I still have some questions here: there seems to be a back and forth in the thread about what the location of the page should be (guides v resources) and the exact content of the header/ subheader. Similarly, it's not clear to me what should be added to the top-level Nav (content from the main doc? The thread in the doc?).

Not sure about next steps?

Created by: bretthayes

@elzannewentzel are we abandoning this index or still waiting on feedback?

Created by: elzannewentzel

It might still be relevant, I'll follow up :)

Created by: bretthayes

@elzannewentzel we could build on this with the upcoming resources/filtering