Remove keys.py and replace with python-dotenv.

- Removed `keys.py`.
- Added `.env.template`.
- Added `.env` to `.gitignore`.
- Updated various files that imported `keys` to use `os.getenv` instead.
- Updated `requirements.txt` dependencies.
- Updated README.md with instructions on setting up environment variables.

This change improves security, flexibility, and makes it easier to use Auto-GPT in notebooks. Environment variables are stored in `.env` and loaded via `load_dotenv()` in `scripts/main.py`.

scripts/speak.py

@@ -1,13 +1,13 @@
 import os
 from playsound import playsound
 import requests
-import keys
+
 
 voices = ["ErXwobaYiN019PkySvjV", "EXAVITQu4vr4xnSDxMaL"]
 
 tts_headers = {
     "Content-Type": "application/json",
-    "xi-api-key": keys.ELEVENLABS_API_KEY
+    "xi-api-key": os.getenv("ELEVENLABS_API_KEY")
 }