docs: Add email alias to Outlook and GMail (#7127)

packages/nodes-base/nodes/Google/Gmail/Gmail.node.json

@@ -51,5 +51,6 @@
 				"url": "https://n8n.io/blog/using-automation-to-boost-productivity-in-the-workplace/"
 			}
 		]
-	}
+	},
+	"alias": ["email"]
 }

packages/nodes-base/nodes/Microsoft/Outlook/MicrosoftOutlook.node.json

@@ -14,5 +14,6 @@
 				"url": "https://docs.n8n.io/integrations/builtin/app-nodes/n8n-nodes-base.microsoftoutlook/"
 			}
 		]
-	}
+	},
+	"alias": ["email"]
 }