#12038935 Education Forum: Update /help courses content text

Related to Automattic/Customer-Education#182

Proposed Changes

Part of the work to remove/move away from the Education forum.

• Task 3: Remove ,and become part of its community from Enroll in a course taught by WordPress experts, and become part of its community.

Before:

After:

Testing Instructions

• Checkout branch or use the live link.
• Navigate to /help, scroll down to the More Resources section, and verify the Courses content has been updated.

Pre-merge Checklist

• Has the general commit checklist been followed? (PCYsg-hS-p2)
• https://wpcalypso.wordpress.com/devdocs/docs/testing/index.md for your changes?
• Have you tested the feature in Simple (P9HQHe-k8-p2), Atomic (P9HQHe-jW-p2), and self-hosted Jetpack sites (PCYsg-g6b-p2)?
• Have you checked for TypeScript, React or other console errors?
• Have you used memoizing on expensive computations? More info in Memoizing with create-selector and Using memoizing selectors and Our Approach to Data
• Have we added the “[Status] String Freeze” label as soon as any new strings were ready for translation (p4TIVU-5Jq-p2)?
• For changes affecting Jetpack: Have we added the “[Status] Needs Privacy Updates” label if this pull request changes what data or activity we track or use (p4TIVU-aUh-p2)?