Document the default scan option for the org

Signed-off-by: Leon <leonvanginneken@gmail.com>

docs/integrations/github/discovery.md

@@ -19,13 +19,17 @@ to the catalog configuration:
 ```yaml
 catalog:
   locations:
+    # (since 0.13.5) Scan all repositories for a catalog-info.yaml in the root of the default branch
     - type: github-discovery
-      target: https://github.com/myorg/service-*/blob/main/catalog-info.yaml
+      target: https://github.com/myorg
+    # Or use a custom pattern for discovering catalog entity descriptor files
+    - type: github-discovery
+      target: https://github.com/myorg/service-*/blob/main/your-own-format.yaml
 ```
 
 Note the `github-discovery` type, as this is not a regular `url` processor.
 
-The target is composed of three parts:
+When using a custom pattern, the target is composed of three parts:
 
 - The base organization URL, `https://github.com/myorg` in this case
 - The repository blob to scan, which accepts \* wildcard tokens. This can simply
@@ -34,7 +38,7 @@ The target is composed of three parts:
 - The path within each repository to find the catalog YAML file. This will
   usually be `/blob/main/catalog-info.yaml`, `/blob/master/catalog-info.yaml` or
   a similar variation for catalog files stored in the root directory of each
-  repository.
+  repository. You could also use a dash (`-`) for referring to the default branch.
 
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