Restructure dev and user guides

[JMoore5353]

This PR moves files around for more consistent/intuitive organization (I believe). Some key changes:

1. Removed the "overview" pages in favor of a page that gets loaded when the user clicks on the relevant heading (e.g. the ROScopter main heading in the user-guide now links to what was previously the roscopter-overview.md page). This reduces clutter.
2. Move ROSflight firmware files that are more user-guide files to the user-guide.
3. Remove ROScopter dev guide files.
4. Update all hyperlinks with the changes in filenames

I did not yet move the rosplane-dev-guide to the user-guide, though @iandareid and I determined that it should be moved, so that I didn't mess up @iandareid current branch worse :)

Closes #8

[Copilot]

Pull request overview

This PR restructures the documentation by reorganizing files for better navigation and reducing clutter. The main changes involve moving files between directories, creating index pages that load when users click navigation headings, and updating all internal hyperlinks to reflect the new structure.

Key changes:

• Enabled navigation.indexes feature in mkdocs to support index pages for navigation sections
• Moved ROSflight firmware documentation from developer-guide to user-guide
• Created index.md files for Tutorials, ROSplane, and ROScopter sections to replace overview pages
• Reorganized "Hardware and ROSflight" section by moving files from concepts/ to hardware-and-rosflight/
• Removed ROScopter developer guide files from the navigation
• Updated all internal documentation links to reflect new file locations

Reviewed changes

Copilot reviewed 26 out of 41 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
mkdocs.yml	Updated navigation structure, enabled navigation.indexes, reorganized sections
docs/user-guide/tutorials/*.md	Updated internal links to reflect moved hardware-and-rosflight files
docs/user-guide/tutorials/index.md	New index page for tutorials section
docs/user-guide/rosplane/*.md	Updated links to index.md and moved files
docs/user-guide/rosplane/index.md	New index page for ROSplane section
docs/user-guide/rosflight-sim/*.md	Updated links to hardware-and-rosflight directory
docs/user-guide/rosflight-firmware/*.md	Updated image paths after move from developer-guide
docs/user-guide/roscopter/index.md	New index page for ROScopter section
docs/user-guide/overview.md	Updated links to new index.md files
docs/user-guide/installation/*.md	Updated links to hardware-and-rosflight directory
docs/user-guide/images/*.{png,svg}	New image files added to user-guide
docs/user-guide/hardware-and-rosflight/*.md	New files for RC and preflight configuration

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[JMoore5353]

I also moved a lot of the files from the "Hardware and ROSflight" section to the rosflight-firmware section, since it seemed like they made more sense there.

@iandareid Please let me know if you think anything needs to be reverted or changed. I think this made the documentation structure more clear, but it could still improve.

[Copilot]

Pull request overview

Copilot reviewed 30 out of 46 changed files in this pull request and generated no new comments.

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