Merge pull request nteract#2990 from alexandercbooth/jext-change

updating changelog for jupyter extension

CHANGELOG.md

@@ -17,6 +17,16 @@ Talk about old and new data explorer features
 
 We're in the beginnings of documenting our components using [react-styleguidist](https://react-styleguidist.js.org/). You can see a sneak preview at [components.nteract.io](https://components.nteract.io).
 
+### Jupyter Extension
+
+Jupyter Extension has some exciting new additions including near menu parity with nteract desktop 🎉
+
+- 📝 We now have a Monaco editor component
+
+- "Open..." has been added to the menu and will redirect the user to the directory listing 
+
+- Notebook cards have been scaled down and padding added to the bottom of the directory listing for easier viewing on smaller screens 
+
 ### Gist publishing
 
 Gist publishing is much more stable now! :octocat: _However_, GitHub no longer allows new anonymous gists. 😢 All gists published from nteract must use authentication. 🔐