chore: added env example for openfga

Author: aaguiarz

auth-for-mcp/fastmcp-mcp-fga-js/.env.example

@@ -3,10 +3,14 @@ AUTH0_AUDIENCE=
 PORT=3001
 MCP_SERVER_URL=http://localhost:3001
 
-# Get these from dashboard.fga.dev / Store Settings
+# For Auth0 FGA Get these from dashboard.fga.dev / Store Settings
 FGA_API_URL='https://api.us1.fga.dev'
 FGA_STORE_ID=<store_id>
 FGA_API_TOKEN_ISSUER='auth.fga.dev'
 FGA_API_AUDIENCE='https://api.us1.fga.dev/'
 FGA_CLIENT_ID='<client_id>'
 FGA_CLIENT_SECRET='<client_secret>'
+
+# For OpenFGA
+FGA_API_URL='https://api.us1.fga.dev'
+FGA_STORE_ID=<store_id>