docs(search): add structured search examples for structured properties (

datahub-project#11565)

docs/how/search.md

@@ -105,6 +105,20 @@ If you want to:
   - ```/q customProperties: encoding*``` [Sample results](https://demo.datahubproject.io/search?page=1&query=%2Fq%20customProperties%3A%20encoding%2A)  
   - Dataset Properties are indexed in ElasticSearch the manner of key=value. Hence if you know the precise key-value pair, you can search using ```"key=value"```. However, if you only know the key, you can use wildcards to replace the value and that is what is being done here.  
 
+- Find an entity with an **unversioned** structured property
+  - ```/q structuredProperties.io_acryl_privacy_retentionTime01:60```
+  - This will return results for an **unversioned** structured property's qualified name `io.acryl.private.retentionTime01` and value `60`.
+  - ```/q _exists_:structuredProperties.io_acryl_privacy_retentionTime01```
+  - In this example, the query will return any entity which has any value for the **unversioned** structured property with qualified name `io.acryl.private.retentionTime01`.
+
+- Find an entity with a **versioned** structured property
+  - ```/q structuredProperties._versioned.io_acryl_privacy_retentionTime.20240614080000.number:365```
+  - This query will return results for a **versioned** structured property with qualified name `io.acryl.privacy.retentionTime`, version `20240614080000`, type `number` and value `365`.
+  - ```/q _exists_:structuredProperties._versioned.io_acryl_privacy_retentionTime.20240614080000.number```
+  - Returns results for a **versioned** structured property with qualified name `io.acryl.privacy.retentionTime`, version `20240614080000` and type `number`.
+  - ```/q structuredProperties._versioned.io_acryl_privacy_retentionTime.\*.\*:365```
+  - Returns results for a **versioned** structured property with any version and type with a values of `365`
+
 - Find a dataset with a column name, **latitude**  
   - ```/q fieldPaths: latitude``` [Sample results](https://demo.datahubproject.io/search?page=1&query=%2Fq%20fieldPaths%3A%20latitude)  
   - fieldPaths is the name of the attribute that holds the column name in Datasets.