Very initial documentation on search kit

docs/the-user-interface/search-kit.md

+# Search kit
+
+Search kit is a new search interface which as of writing (5.36) is
+in beta mode. It ships as an extension when you can enable on 
+the extensions screen in releases from 5.29 onwards. However it has
+developed rapidly and we strongly recommend that if you are exploring
+it you do so on the latest version of CiviCRM. The functionality
+that is in this section is based on CiviCRM 5.36 and may not
+be present in earlier versions. It may also change visually.
+
+!!! note Search kit ships as an extension as part of our strategy of
+putting significant functionality leaps into extensions rather than 
+overhauling existing code. This allows us to demarcate rapidly evolving
+code and to keep long-standing code more stable. People can opt into 
+the extension or not. However it is maintained as part of core against
+the specific release it ships with (as it is closely tied to apiv4 
+functionality).
+
+# Search components
+
+There are 3 components to search kit. Depending on what you are doing you
+may not use all 3
+
+1) The search screen 
+   - this is where the search criteria and available fields are configured
+2) Search displays
+   - a search can have no search displays or it can have one or multiple.
+    search displays currently available are table views, list views or smart 
+     groups
+3) Search form
+   - in order to add a search form it is necessary to have the form
+    builder (afform gui) extension that ships with core enabled.
+
+# The search screen
+
+The search screen is reached from the search listing page (Search->Search Kit)
+![img.png](../img/the-user-interface/search-kit/search-listing.png)
+
+The screen below shows a very basic search for contacts with no entry for
+camera skill level. This is 
+![img.png](../img/the-user-interface/search-kit/basic-search.png)
+
+# Search displays
+
+Search displays are added from the Search screen once a search has 
+been saved.
+
+![img.png](../img/the-user-interface/search-kit/search-display.png)
+
+# Search forms
+
+Search forms are forms that can be exposed as web pages
+or as dashlets (in future other options will exist). They 
+can have exposed filters. For example
+
+![img.png](../img/the-user-interface/search-kit/search-dashlet.png)
+
+They are added via the search listing
+
+![img.png](../img/the-user-interface/search-kit/add-form.png)
+