Adding FriendGrid example node (updated version of the one in the n8n docs)

credentials/FriendGridApi.credentials.ts

@@ -0,0 +1,21 @@
+import {
+	ICredentialType,
+	NodePropertyTypes,
+} from 'n8n-workflow';
+
+export class FriendGridApi implements ICredentialType {
+	name = 'friendGridApi';
+	displayName = 'FriendGrid API';
+	documentationUrl = 'friendGrid';
+	properties = [
+		// The credentials to get from user and save encrypted.
+		// Properties can be defined exactly in the same way
+		// as node properties.
+		{
+			displayName: 'API Key',
+			name: 'apiKey',
+			type: 'string' as NodePropertyTypes,
+			default: '',
+		},
+	];
+}