docs: removing external links for unified nav (#1531)

Author: haleychaas

docs/english/_sidebar.json

@@ -202,21 +202,5 @@
 				"items": ["tools/bolt-python/ja-jp/legacy/steps-from-apps"]
 			}
 		]
-	},
-	{ "type": "html", "value": "<hr>" },
-	{
-		"type": "link",
-		"label": "Release notes",
-		"href": "https://github.com/slackapi/bolt-python/releases"
-	},
-	{
-		"type": "link",
-		"label": "Code on GitHub",
-		"href": "https://github.com/SlackAPI/bolt-python"
-	},
-	{
-		"type": "link",
-		"label": "Contributors Guide",
-		"href": "https://github.com/SlackAPI/bolt-python/blob/main/.github/contributing.md"
 	}
 ]

docs/english/index.md

@@ -13,6 +13,10 @@ If you otherwise get stuck, we're here to help. The following are the best ways
 * [Issue Tracker](http://github.com/slackapi/bolt-python/issues) for questions, bug reports, feature requests, and general discussion related to Bolt for Python. Try searching for an existing issue before creating a new one.
 * [Email](mailto:support@slack.com) our developer support team: `support@slack.com`.
 
+## Release notes
+
+Check out the [Bolt for Python release notes](https://github.com/slackapi/bolt-python/releases) for all the latest happenings.
+
 ## Contributing
 
 These docs live within the [Bolt-Python](https://github.com/slackapi/bolt-python/) repository and are open source.