Add description to eleven labs credentials

packages/components/credentials/ElevenLabsApi.credential.ts

@@ -4,12 +4,15 @@ class ElevenLabsApi implements INodeCredential {
     label: string
     name: string
     version: number
+    description: string
     inputs: INodeParams[]
 
     constructor() {
         this.label = 'Eleven Labs API'
         this.name = 'elevenLabsApi'
         this.version = 1.0
+        this.description =
+            'Sign up for a Eleven Labs account and <a target="_blank" href="https://elevenlabs.io/app/settings/api-keys">create an API Key</a>.'
         this.inputs = [
             {
                 label: 'Eleven Labs API Key',