Tweak "Configure learning mode" task description

[donnapep]

Resolves #7345.

Proposed Changes

Updates the "Configure learning mode" task description.

Testing Instructions

1. Execute the following SQL - delete from wp_options where option_name like '%sensei_home_task_%.
2. Go to Sensei LMS > Home.
3. Check that there is a task that says "Configure Learning Mode, an immersive and distraction-free view for students".

Pre-Merge Checklist

• PR title and description contain sufficient detail and accurately describe the changes
• Acceptance criteria is met
• Decisions are publicly documented
• Adheres to coding standards (PHP, JavaScript, CSS, HTML)
• All strings are translatable (without concatenation, handles plurals)
• Follows our naming conventions (P6rkRX-4oA-p2)
• Hooks (p6rkRX-1uS-p2) and functions are documented
• New UIs are responsive and use a mobile-first approach
• New UIs match the designs
• Different user privileges (admin, teacher, subscriber) are tested as appropriate
• Legacy courses (course without blocks) are tested
• Code is tested on the minimum supported PHP and WordPress versions
• User interface changes have been tested on the latest versions of Chrome, Firefox and Safari
• "Needs Documentation" label is added if this change requires updates to documentation
• Known issues are created as new GitHub issues

[github-actions]

Test the previous changes of this PR with WordPress Playground.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 51.92%. Comparing base (8450ab6) to head (46c9479).
Report is 1 commits behind head on trunk.

Additional details and impacted files

@@            Coverage Diff            @@
##              trunk    #7540   +/-   ##
=========================================
  Coverage     51.92%   51.92%           
  Complexity    11265    11265           
=========================================
  Files           630      630           
  Lines         47683    47683           
  Branches        421      421           
=========================================
  Hits          24759    24759           
  Misses        22587    22587           
  Partials        337      337           

Files	Coverage Δ
...class-sensei-home-task-configure-learning-mode.php	27.27% <0.00%> (ø)

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update ddc175e...46c9479. Read the comment docs.