Update for Copilot Free (#247)

* docs: Clarify prerequisites

* docs: Update reference links to newer docs

.github/steps/X-finish.md

@@ -18,8 +18,8 @@ Here's a recap of all the tasks you completed:
 
 ### Additional learning and resources
 
-- [Copilot for Individuals](https://docs.github.com/en/copilot/overview-of-github-copilot/about-github-copilot-for-individuals)
-- [Copilot for Business](https://docs.github.com/en/copilot/overview-of-github-copilot/about-github-copilot-for-business)
+- [What is GitHub Copilot](https://docs.github.com/en/copilot/about-github-copilot/what-is-github-copilot)
+- [About enterprise accounts for Copilot Business](https://docs.github.com/en/enterprise-cloud@latest/admin/copilot-business-only/about-enterprise-accounts-for-copilot-business)
 - [Getting started with Copilot](https://docs.github.com/en/copilot/getting-started-with-github-copilot/getting-started-with-github-copilot-in-visual-studio-code)
 - [Configure Copilot settings](https://docs.github.com/en/copilot/configuring-github-copilot/configuring-github-copilot-settings-on-githubcom)
 

README.md

@@ -28,7 +28,9 @@ GitHub Copilot can help you code by offering autocomplete-style suggestions. You
 - **Who this is for**: Developers, DevOps Engineers, Software development managers, Testers.
 - **What you'll learn**: How to install Copilot into a Codespace, accept suggestions from code, accept suggestions from comments.
 - **What you'll build**: Javascript files that will have code generated by Copilot AI for code and comment suggestions.
-- **Prerequisites**: To use GitHub Copilot you must have an active GitHub Copilot subscription. Sign up for 30 days free [Copilot](https://github.com/settings/copilot).
+- **Prerequisites**: 
+  - [GitHub account](https://github.com/login) - With available Codespaces minutes.
+  - [GitHub Copilot](https://github.com/github-copilot/signup) - For learning, the **Copilot Free** option with usage limits should be sufficient.
 - **Timing**: This course can be completed in under an hour.
 
 ### How to start this course