Allow to override log level for specific target (#4305)

.env.template

@@ -362,8 +362,9 @@
 ## Log level
 ## Change the verbosity of the log output
 ## Valid values are "trace", "debug", "info", "warn", "error" and "off"
-## Setting it to "trace" or "debug" would also show logs for mounted
-## routes and static file, websocket and alive requests
+## Setting it to "trace" or "debug" would also show logs for mounted routes and static file, websocket and alive requests
+## For a specific module append a comma separated `path::to::module=log_level`
+## For example, to only see debug logs for icons use: LOG_LEVEL="info,vaultwarden::api::icons=debug"
 # LOG_LEVEL=info
 
 ## Token for the admin interface, preferably an Argon2 PCH string