web: add FLoC environment variable

ENABLE_FLOC, defaulting to false.

env.example

@@ -357,6 +357,10 @@ JIBRI_LOGS_DIR=/config/logs
 # Disable HTTPS: handle TLS connections outside of this setup
 #DISABLE_HTTPS=1
 
+# Enable FLoC
+# Opt-In to Federated Learning of Cohorts tracking
+#ENABLE_FLOC=0
+
 # Redirect HTTP traffic to HTTPS
 # Necessary for Let's Encrypt, relies on standard HTTPS port (443)
 #ENABLE_HTTP_REDIRECT=1