Add note about .env files from parent folders

It was extremely confusing to me why an API key was being used within
VSCode terminal that wasn't my OpenInterpreter key.
This note might save other people time.

Author: endolith

interpreter/core/llm/llm.py

@@ -3,6 +3,9 @@
 os.environ["LITELLM_LOCAL_MODEL_COST_MAP"] = "True"
 import sys
 
+# Note: litellm in DEV mode will load .env files from the current directory
+# and all parent directories. This can lead to unexpected API keys being loaded
+# if there are .env files in parent folders.
 import litellm
 
 litellm.suppress_debug_info = True