added an introduction explaining the why

Signed-off-by: Fabrice Flore-Thébault <[email protected]>

Author: themr0c

modules/integrating-with-github/proc-enabling-github-repository-discovery.adoc

@@ -1,7 +1,9 @@
 [id="enabling-github-repository-discovery"]
 = Enabling GitHub repository discovery
 
-To enable integration with the GitHub API, configure the GitHub integration in {product}.
+By default, you register components manually into {product}.
+Consider configuring {product-short} to discover your GitHub repositories automatically.
+When a repository contains a `catalog-info.yaml` file, {product-short} ingests the entity into the catalog as a component.
 
 .Prerequisites
 * You link:{configuring-book-url}[added a custom {product-short} application configuration], and have sufficient permissions to modify it.
@@ -94,7 +96,8 @@ Select `Only on this account`.
 * **Private key**
 * **Webhook secret**
 
-. To add your GitHub credentials to {product-short}, add the following key/value pairs to link:{configuring-dynamic-plugins-book-url}#provisioning-your-custom-configuration[your {product-short} secrets]:
+. To add your GitHub credentials to {product-short}, add the following key/value pairs to link:{configuring-dynamic-plugins-book-url}#provisioning-your-custom-configuration[your {product-short} secrets].
+You can use these secrets in the {product-short} configuration files by using their respective environment variable name.
 +
 `INTEGRATION_GITHUB_APP_ID`::
 Enter the saved **App ID**.