add quick tutorial on google drive <-> colab

Hack/README.md

@@ -1,3 +1,16 @@
 # Hack Resources
 
-[data](https://drive.google.com/drive/u/1/folders/13ySEme-B8XDMYgTZ8_rVpMarRUUGYbTw)
+[google drive for data](https://drive.google.com/drive/u/1/folders/13ySEme-B8XDMYgTZ8_rVpMarRUUGYbTw)
+
+It is most straightforward to directly work with the above Google drive from colab,
+since the files don't need to leave Google's servers in that case.
+The way I figured out how to do this is as follows (there might be a better method):
+1. open the above Google drive.
+2. right-click on the file or folder you need.
+3. click "Organize" -> "Add shortcut".
+4. in "All locations", choose "My Drive" and click "Add".
+5. in the colab instance, open the "Files" explorer on the left.
+6. click "Mount Drive" icon.
+7. you should be able to see the file now.
+   To switch the colab working directory to your drive, type:
+   ``cd "/content/drive/MyDrive/"``