[Feature]: Add new AF guidance on dashboards

### Description

Add information to dashboard pages about AF's new dashboard guidance: https://analysisfunction.civilservice.gov.uk/policy-store/?keyword=dashboards&area=&doctype=&submit=Go

### Use case

This guidance will be helpful for users who are looking to create dashboard especially the examples and software parts.

### Why this is important

It will also be helpful for SDT to signpost teams to it.

### Additional Context

We get dashboard questions in the mailboxes and this would be a handy resource for PPs as well.

Start by locating the dashboard pages in the analysts-guide site and review the linked Analysis Function dashboard guidance, especially its examples and software information. Done means the relevant pages clearly signpost this guidance for analysts, SDT, and PPs seeking dashboard advice.

Written by the indexing model from the issue text.