file tidying

[NGRhodes]

No description provided.

[Copilot]

Pull Request Overview

This PR tidies up the documentation by reorganizing session files and updating chapter titles.

• Added a new wrap-up session for Session 7.
• Revised Session 5 (Job Scheduling & Submission) with updated headers and practical instructions.
• Removed the Session 6 file and introduced a new best practices and troubleshooting guide, with corresponding updates to the Table of Contents.

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
book/wrap-up.md	New wrap-up session file with session summary headings.
book/scheduling-submission.md	Updated session title and section headers; refined practical content.
book/part6.md	Removed outdated session file.
book/best-practices-troubleshooting.md	Added new session file detailing troubleshooting strategies.
book/_toc.yml	Updated Table of Contents to reflect the new file organization.

Comments suppressed due to low confidence (2)

book/scheduling-submission.md:8

• [nitpick] Consider using a consistent title case for section headings, e.g., '### Resource Requests', to align with the formatting of other headings.

### resource requests

book/scheduling-submission.md:12

• [nitpick] Update the section header to title case (e.g., '## Exercise') for consistency with other session headings.

## exercise