Restructure and start working on CLI

zed/src/lib.rs

@@ -0,0 +1,17 @@
+use zed_extension_api as zed;
+
+struct JRPCSyntaxExtension {
+    // ... state
+}
+
+impl zed::Extension for JRPCSyntaxExtension {
+    fn new() -> Self
+    where
+        Self: Sized,
+    {
+        todo!()
+    }
+    // ...
+}
+
+zed::register_extension!(JRPCSyntaxExtension);