MATTER-5791: Update custom cluster instructions

sld250-matter-references/custom-matter-device.md

@@ -122,4 +122,17 @@ $ mattertool levelcontrol read current-level 1 1 // Returns 10
 
 ## Defining a Custom Cluster
 
-Create an XML file with custom cluster definitions. For an example, see [Sample MEI Cluster](https://github.com/project-chip/connectedhomeip/blob/master/src/app/zap-templates/zcl/data-model/chip/sample-mei-cluster.xml). In ZAP click 'Extensions' and add the XML file. The newly defined cluster can then be enabled in any endpoint under the domain for which it was defined (for example General), its Commands and Attributes can be managed like those of any other cluster.
+In order to use a custom cluster in an application, follow these steps:
+- Create an XML file with custom cluster definitions. For an example, see [Sample MEI Cluster](https://github.com/project-chip/connectedhomeip/blob/master/src/app/zap-templates/zcl/data-model/chip/sample-mei-cluster.xml). 
+- In ZAP click 'Extensions' and add the XML file. The newly defined cluster can then be enabled in any endpoint under the domain for which it was defined (for example General), its Commands and Attributes can be managed like those of any other cluster. Click Ctrl+S to save the changes.
+- Manually edit the project's .zap file (located in config/zap/ in the project directory) to add the following block   
+ ```xml  
+    {
+      "key": "generateStaticTemplates",
+      "value": "true"
+    }   
+ ```
+to the "keyValuePairs" array. For en example see [Sample ZAP file](https://github.com/SiliconLabsSoftware/matter_extension/blob/v2.8.0-rc3/slc/apps/performance-test-app/thread/performance-test-app.zap)
+- Install the "Custom ZAP generation" component under Silicon Labs Matter -> Stack in the project's Component Editor. 
+
+

sld250-matter-references/matter-zap.md

@@ -194,4 +194,15 @@ The image above is what the multiple device type endpoints looks like after conf
 
 ## Defining a Custom Cluster
 
-Create an XML file with custom cluster definitions, for an example see [Sample MEI Cluster](https://github.com/project-chip/connectedhomeip/blob/master/src/app/zap-templates/zcl/data-model/chip/sample-mei-cluster.xml). In ZAP click 'Extensions' and add the XML file. The newly defined cluster can then be enabled in any endpoint under the domain for which it was defined (for example General), its Commands and Attributes can be managed like those of any other cluster.
+In order to use a custom cluster in an application, follow these steps:
+- Create an XML file with custom cluster definitions. For an example, see [Sample MEI Cluster](https://github.com/project-chip/connectedhomeip/blob/master/src/app/zap-templates/zcl/data-model/chip/sample-mei-cluster.xml). 
+- In ZAP click 'Extensions' and add the XML file. The newly defined cluster can then be enabled in any endpoint under the domain for which it was defined (for example General), its Commands and Attributes can be managed like those of any other cluster. Click Ctrl+S to save the changes.
+- Manually edit the project's .zap file (located in config/zap/ in the project directory) to add the following block   
+ ```xml  
+    {
+      "key": "generateStaticTemplates",
+      "value": "true"
+    }   
+ ```
+to the "keyValuePairs" array. For en example see [Sample ZAP file](https://github.com/SiliconLabsSoftware/matter_extension/blob/v2.8.0-rc3/slc/apps/performance-test-app/thread/performance-test-app.zap)
+- Install the "Custom ZAP generation" component under Silicon Labs Matter -> Stack in the project's Component Editor. 

sld601-matter-application-development/index.md

@@ -4,3 +4,4 @@ This section covers application development topics. Silicon Labs will build out
 
 - [Matter Scenes Quick Start Guide](./matter-scenes-quick-start-guide)
 - [Matter Event and Timer Guide](./matter-event-timer-guide.md)
+- [Implementing Cluster Functionality in an Application](matter-application-cluster-logic.md)