update "master" to "main"

Author: lmkeston

responses/08e-list.md

@@ -8,7 +8,7 @@ Let's try again!
 
 ### :keyboard: Create a list of your favorite sites
 
-1. Edit the `index.html` file in your master branch by [using this direct link](https://github.com/{{ user.username }}/{{ repo }}/edit/master/index.html) or going to the **Code** tab, clicking on the `index.html` file, clicking the pencil :pencil: to edit the HTML.
+1. Edit the `index.html` file in your main branch by [using this direct link](https://github.com/{{ user.username }}/{{ repo }}/edit/main/index.html) or going to the **Code** tab, clicking on the `index.html` file, clicking the pencil :pencil: to edit the HTML.
 1. Inside the body tag, create a list, either ordered or unordered, of your favorite sites on the interwebs.
 1. In the _Commit changes_ section, enter a commit message that describes what you've done.
 1. Ensure you've selected _Create a new branch for this commit and start a pull request_.
@@ -18,4 +18,4 @@ Let's try again!
 1. Click on **Create pull request.**
 
 <hr>
-<h3 align="center">I'll respond in your new pull request.</h3>
+<h3 align="center">I'll respond in your new pull request.</h3>