Update azuredevops.mdx (#1746)

Updated the page to include the recently Added `repos` field to Azure
DevOps external service for explicit repository selection

Author: mibali

docs/admin/code-hosts/azuredevops.mdx

@@ -39,15 +39,19 @@ Next, configure the code host connection by following the next steps:
     	"username": "<admin username>",
     	"token": "<admin token>",
     	"projects": ["org1/project1"],
-    	"orgs": ["org2"]
+    	"orgs": ["org2"],
+		"repos": [
+		    "myorg/myproject/myrepo1", 
+		    "myorg/myproject/myrepo2"
+		  ]
     }
     ```
 
 1. Select **Add repositories**.
 
 ## Repository syncing
 
-Currently, all repositories belonging to the configured organizations/projects will be synced.
+All repositories within the configured organizations/projects are synced by default, but you can also choose to sync either all repositories or only specific repositories from those organizations/projects.
 
 In addition, you may exclude one or more repositories by setting the [`exclude`](/admin/code-hosts/azuredevops#configuration) field in the code host connection.
 
@@ -127,6 +131,13 @@ Azure DevOps connections support the following configuration options, which are
 	//   ]
 	"projects": null,
 
+	// An array of "org/project/repo" strings specifying which Azure DevOps repositories within a project should be mirrored in Sourcegraph.
+	"repos": [
+	    "myorg/my-project/myrepo",        // Format: <organization>/<project>/<repository>
+	    "myorg/myproject/myproject",     // Format: repository where project and repo share the same name
+	    "myorg/my project/my project"    // Format: spaces in project or repository names
+  	]
+
 	// Rate limit applied when making background API requests.
 	"rateLimit": {
 		"enabled": false,