docs: small thing on ui

Author: nperez0111

adr/2025_06_18-ui-components.md

@@ -0,0 +1,9 @@
+# BlockNote UI
+
+## Lightweight JSX
+
+There is a large difference between UI components defined in the core library compared to the ones in the react package. The paradigms are very different due to the low-level elements in the core library, ideally we could bring this closer together without completely depending on react for the core library.
+
+## Theming
+
+There are several approaches here that would require a lot more research and discussion.