Migrate Skills Exercise from README -> Issue based flow

[wolz-CODElife]

Summary

This PR enhances the connect-the-dots skills exercise by converting it to an Issue-based flow, ensuring dynamic issue references, and improving workflow reliability and modularity. The changes support a scalable learner experience with better debugging and progression tracking.

Changes

• Set write permissions for contents, actions, and issues to enable workflow operations.
• Defined the template files(STEP_1_FILE, STEP_2_FILE, ...,STEP_n_FILE) as environment variable for consistent template referencing.
• Implemented start_exercise job using skills/exercise-toolkit/[email protected] to initialize the exercise and output the issue URL.
• Added post_next_step_content job to:
  • Create dynamic issues ("Fix the broken sidebar" and "Sidebar bug again") using actions/github-script@v7.
  • Prepare file history with _sidebar.md updates and commit SHA storage.
  • Build and post content with action-text-variables@v1, using {{original_issue}} and {{duplicate_issue}} for dynamic referencing.
  • Made issue identifiers {{original_issue}} and {{duplicate_issue}} dynamic, replacing hardcoded values to support multiple concurrent issue creations.
  • Change the navigation system to use: gh workflow enable
• Added find_exercise job to locate the exercise issue using skills/exercise-toolkit.
• Added check_step_work and verify_step_work jobs to:
  • Post "checking work" feedback and verify learner progress.
  • Use actions/github-script@v7 for context debugging and output tracking.
• Enhanced post_next_step_content with dynamic content and workflow toggling.

Closes: #94

Task list

• For workflow changes, I have verified the Actions workflows function as expected.
• For content changes, I have reviewed the style guide.