JS: Add change note

Author: asgerf

javascript/change-notes/2021-03-29-misc-steps.md

@@ -0,0 +1,6 @@
+lgtm,codescanning
+* The `lodash-es` package is now recognized as a variant of `lodash`.
+* Taint is now propagated through the `babel.transform` function.
+* Improved data flow through React applications using `redux-form` or `react-router`.
+* Base64 decoding using the `react-native-base64` package is now recognized.
+* An expression of form `o[o.length] = y` is now recognized as appending to an array.