✨ Add DHL node (#2385)

* ✨ DHL node

* ⚡ Add credentials verfication

* 👕 Nodelinter pass

* ⚡ Improvements

* ⚡ Fix node name

Co-authored-by: Iván Ovejero <ivov.src@gmail.com>
Co-authored-by: Jan Oberhauser <jan.oberhauser@gmail.com>

packages/nodes-base/credentials/DhlApi.credentials.ts

@@ -0,0 +1,18 @@
+import {
+	ICredentialType,
+	INodeProperties,
+} from 'n8n-workflow';
+
+export class DhlApi implements ICredentialType {
+	name = 'dhlApi';
+	displayName = 'DHL API';
+	documentationUrl = 'dhl';
+	properties: INodeProperties[] = [
+		{
+			displayName: 'API Key',
+			name: 'apiKey',
+			type: 'string',
+			default: '',
+		},
+	];
+}