Merge pull request #1 from source-academy/master

some updates

Author: gerhean

README.md

@@ -21,6 +21,18 @@ In package.json, change line 19:
 to:
 "start-js": "set PORT=80 & react-scripts-ts start",
 
+## For Testing of js-slang
+
+1. For now, use the branch 'update-js-slang' in cadet-frontend
+2. Follow the instructions on js-slang to transpile your own copy
+3. Edit line 41 of package.json in this project to link to the directory of your js-slang and then run `yarn`:
+
+`"js-slang": "file:path/to/js-slang",`
+
+Note that this copies your files over, any future changes will not be reflected. 
+
+You may try [this](https://medium.com/@alexishevia/the-magic-behind-npm-link-d94dcb3a81af) for a smoother experience.
+
 ## Application Structure
 
 1. `actions` contains action creators, one file per reducer, combined in index.