feat: add instructions for Google collab

Author: sanjayankur31

notebooks/Python_HH_version/README.md

@@ -26,5 +26,34 @@ This notebook was developed as part of [Google Summer of Code 2022 by Rahul Sonk
 
 *Advantage: quick to start & run, no login required*
 
-- The notebook can also be opened using [Binder](https://mybinder.org/). Click here to open the HH notebook: [![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/openworm/hodgkin_huxley_tutorial/master?labpath=notebooks%2FPython_HH_version%2FPython_Notebook_HH.ipynb)
+- The notebook can also be opened using [Binder](https://mybinder.org/). Click here to open the HH notebook: [![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/openworm/hodgkin_huxley_tutorial/master?labpath=notebooks%2FPython_HH_version%2FPython_Notebook_HH.ipynb)-
 - You should be able to run the interactive widget by click the double arrow (▶▶) in the JupyterLab toolbar at the top of the notebook.
+
+### Option 3) Using Google Collab
+
+*Advantage: can store your progress on your Google drive, but requires Google account and additional setup*
+
+- The notebook can also be opened in [Google Collab](https://colab.research.google.com/github/openworm/hodgkin_huxley_tutorial/blob/master/notebooks/Python_HH_version/Python_Notebook_HH.ipynb), but you will need to add a new cell to the top of the notebook and paste the following to set it up to run properly:
+
+
+    from google.colab import output
+    output.enable_custom_widget_manager()
+
+    from google.colab import drive
+    drive.mount("/content/gdrive")
+
+    %cd /content/gdrive/MyDrive
+    !ls
+    !rm -rf hodgkin_huxley_tutorial  # remove this line if you do not want to remove your existing copy to create a new one
+    !git clone --depth 1 https://github.com/openworm/hodgkin_huxley_tutorial/
+    %cd hodgkin_huxley_tutorial/
+    !pip install -r requirements.txt
+    %cd notebooks/Python_HH_version/
+
+
+This does the following:
+
+- asks you to allow Google Collab access your Google Drive when run for the first time: please allow all permissions
+- mounts your Google Drive
+- copies the GitHub repositoriy into it under the "hodgkin_huxley_tutorial" folder
+- installs the required Python packages