Merge pull request #270 from ataiya/patch-1

Improved extension install instructions for lab vs. notebook

Author: vidartf

README.md

@@ -16,10 +16,19 @@ Using pip:
 
 ```bash
 pip install pythreejs
+```
+
+And then install the extension for jupyter notebooks
+```
 jupyter nbextension install --py --symlink --sys-prefix pythreejs
 jupyter nbextension enable --py --sys-prefix pythreejs
 ```
 
+Or for jupyter lab:
+```
+jupyter labextension install jupyter-threejs
+```
+
 Note for developers: the `--symlink` argument on Linux or OS X allows one to
 modify the JavaScript code in-place. This feature is not available
 with Windows.