📙 docs: More Info on GOOGLE_APPLICATION_CREDENTIALS (#177)

Author: EliRibble

README.md

@@ -87,7 +87,7 @@ The following environment variables are required to run the application:
 - `AWS_ACCESS_KEY_ID`: (Optional) needed for bedrock embeddings
 - `AWS_SECRET_ACCESS_KEY`: (Optional) needed for bedrock embeddings
 - `AWS_SESSION_TOKEN`: (Optional) may be needed for bedrock embeddings
-- `GOOGLE_APPLICATION_CREDENTIALS`: (Optional) needed for Google VertexAI embeddings
+- `GOOGLE_APPLICATION_CREDENTIALS`: (Optional) needed for Google VertexAI embeddings. This should be a path to a service account credential file in JSON format, as accepted by [langchain](https://python.langchain.com/api_reference/google_vertexai/index.html)
 - `RAG_CHECK_EMBEDDING_CTX_LENGTH` (Optional) Default is true, disabling this will send raw input to the embedder, use this for custom embedding models.
 
 Make sure to set these environment variables before running the application. You can set them in a `.env` file or as system environment variables.