Update README.md

Author: Sepand Parhami

README.md

@@ -14,3 +14,19 @@ Helps with writing tests for animations by pausing then and allowing control of
 the progress of animations on the page. You can pause an animation part way
 through and do a screenshot based test or simply validate the position or
 dimensions of elements.
+
+## Developing
+
+### Build
+
+```shell
+npm run build
+npm run build-watch
+```
+
+### Test
+
+```shell
+npm run test
+npm run test-watch
+```