[ADF- 2670] Checked and updated docs for 2.3 (#3197)

* [ADF-2670] Reviewed docs for 2.3 with only minor changes

* [ADF-2670] Checked and updated docs for 2.3

docs/content-services/search-query-builder.service.md

@@ -0,0 +1,57 @@
+---
+Added: v2.3.0
+Status: Active
+---
+
+# Search Query Builder service
+
+Stores information from all the custom search and faceted search widgets, compiles and runs the final Search query.
+
+## Class members
+
+### Methods
+
+-   `addFilterQuery(query: string): void`  
+    Adds a filter query to the search.  
+    -   `query` - Query text
+-   `removeFilterQuery(query: string): void`  
+    Removes a previously added filter query from the search.  
+    -   `query` - Query text
+-   `getFacetQuery(label: string): FacetQuery`  
+    Gets a facet query.  
+    -   `label` - Identifier of the target query
+-   `update(): void`  
+    Rebuilds the query and triggers the `updated` event.  
+-   `async execute()`  
+    Executes the query.  
+-   `buildQuery(): QueryBody`  
+    Builds the query.  
+
+## Details
+
+The Query Builder is UI agnostic and does not rely on Angular components.
+You can reuse it with multiple component implementations.
+
+You can use custom widgets to populate and edit the following parts of the resulting query:
+
+- categories
+- query fragments that form query expression
+- include fields
+- scope settings
+- filter queries
+- facet fields
+- range queries
+
+```ts
+constructor(queryBuilder: SearchQueryBuilderService) {
+
+    queryBuilder.updated.subscribe(query => {
+        this.queryBuilder.execute();
+    });
+
+    queryBuilder.executed.subscribe(data => {
+        this.onDataLoaded(data);
+    });
+
+}
+```