changed the base URL to have main instead of master in the path

Task 2: Create a new HTTP dataset to use as a source

moviesDB url is change **master** to **main**

data20/demos/README.md

@@ -51,7 +51,7 @@ The main tasks for this exercise are as follows:
 
 1. In the New Linked Service (HTTP) screen, specify the url of the moviesDB csv file. You can access the data with no authentication required using the following endpoint:
 
-    https://raw.githubusercontent.com/microsoft/ignite-learning-paths-training-data/master/data20/demos/moviesDB.csv
+    https://raw.githubusercontent.com/microsoft/ignite-learning-paths-training-data/main/data20/demos/moviesDB.csv
 
 1. Place this in the **Base URL** text box. 
 
@@ -107,4 +107,4 @@ At this point, you have fully configured your copy activity. To test it out, cli
 1. To verify the copy worked as expected, open up your ADLS gen2 storage account and check to see your file was written as expected
 1. **Important:** In order to proceed with the next demo - click **Publish All** to deploy the pipeline to the factory
 
-💡 NOTE - At the end of this demo, if you are NOT going through any other demos - delete the resource group to reduce and mimize Azure spend.
+💡 NOTE - At the end of this demo, if you are NOT going through any other demos - delete the resource group to reduce and mimize Azure spend.