Add huggingface inference as text completion source

src/endpoints/secrets.js

@@ -41,6 +41,7 @@ const SECRET_KEYS = {
     GROQ: 'api_key_groq',
     AZURE_TTS: 'api_key_azure_tts',
     ZEROONEAI: 'api_key_01ai',
+    HUGGINGFACE: 'api_key_huggingface',
 };
 
 // These are the keys that are safe to expose, even if allowKeysExposure is false