TILES-6624 Describe demo

README.md

@@ -1,8 +1,21 @@
 # MapGL Shadows
 
+This monorepo contains lighting utils for [MapGL JS API](https://docs.2gis.com/en/mapgl/overview).
+
+For now, is has only [shadows demo](#demo) app.
+
 ## Demo
 
-TBD
+You can inspect demo by navigating to https://2gis.github.io/lighting-control/. Some specific places:
+
+- [The Burj Khalifa, Dubai](https://2gis.github.io/lighting-control/?lng=55.273020&lat=25.195524);
+- [The Red Square, Moscow](https://2gis.github.io/lighting-control/?lng=37.622656&lat=55.752770).
+
+![Demo app example](./assets/demo.png "Title")
+
+### Specific date and time
+
+Demo app allows you to select specific date (using datepicker) and time (using slider). Map lighting will be updated on every date/time change. Also, time lapse may be enabled.
 
 ## Lighting control plugin