update branch references to main

README.md

@@ -1,5 +1,5 @@
 # Introduction to Python for Data Science
-[![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/uc-python/intro-python-datasci/master?urlpath=lab)
+[![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/uc-python/intro-python-datasci/main?urlpath=lab)
 
 ### Course Description
 
@@ -72,7 +72,7 @@ These easiest way to install Python, Jupyter, and the necessary packages is thro
 There are two ways to download the class materials:
 
 1. Clone it - If you're familiar with how to do so, you can clone this repository.
-2. Download the files as a zip - use [this link](https://github.com/uc-python/intro-python-datasci/archive/master.zip)
+2. Download the files as a zip - use [this link](https://github.com/uc-python/intro-python-datasci/archive/refs/heads/main.zip)
 
 ### Questions
 

notebooks/00-Introduction.ipynb

@@ -411,7 +411,7 @@
     }
    },
    "source": [
-    "* You can either access this material through [Binder](https://mybinder.org/v2/gh/uc-python/intro-python-datasci/master) or by [downloading the material](https://github.com/uc-python/intro-python-datasci/archive/master.zip)\n",
+    "* You can either access this material through [Binder](https://mybinder.org/v2/gh/uc-python/intro-python-datasci/main) or by [downloading the material](https://github.com/uc-python/intro-python-datasci/archive/refs/heads/main.zip)\n",
     " and opening it via Anaconda Navigator and JupyterLab."
    ]
   },