docs: mention REST API as a usage surface in README intro

Author: aimproxy

README.md

@@ -1,7 +1,8 @@
 # LavaQL
 
 LavaQL's query language lets you run analytics queries against any data source.
-You can use LavaQL through the playground, directly in code editors via the LSP, or embedded as a web component in your own tools.
+You can use LavaQL through the playground, directly in code editors via the LSP,
+embedded as a web component in your own tools, or via the REST API to power backends and apps.
 
 ## Architecture