Manage dashboard links: Improve structure and clarity

The term dashboard link is used interchangeably to talk about where a link is placed and where a link is pointing to, which makes this page very confusing. The structure of the page isn't as logical as it could be. Also there are terms on this page that are used without first being defined. ### Tasks - [ ] Clarify whether we're talking about where you link from or where you link to; remove potentially confusing drill down" language - [x] Define and document tasks for adding different link types - [x] Decide how the content should be grouped and determine page headings - [ ] Define relevant terms - [ ] Update section intro text accordingly - [ ] Rewrite intro section specifically about choosing your link type - [ ] ~~Define data link in intro (add a glossary term?)~~ - [ ] Explain how dashboard links help the issue of struggling to find context - [x] Remove **Controlling time range using the URL** section (maybe mistakenly placed here because it's sort of about links) - In both the add dashboard link and panel link sections this info is there but not clear in terms of how it works in a real example when setting a time range in a URL **Dashboard links** - [x] Clarify reference to "other types of links" - [ ] **Add links to dashboards** - [x] Clarify meaning of dashboard links; currently page uses this to mean both where they are in your dashboard and a link type that you're using - [x] Clarify that adding dashboard links means linking to **ALL** your dashboards; explain the use case for this (not clear) - [x] Consolidate **Update, Duplicate,** and **Delete** sections into one section (maybe Manage). Or add the duplication step as part of adding one and remove update and delete (Note: Duplicate is at the wrong heading level)