Update documentation for clarity and consistency

[kendonB]

Docs: fix sidebar links, clean Docsify index, and polish wording

Description

• Rearranged links in _sidebar.md for better organization and fixed broken quoted paths.
• Updated docs/index.html title and meta description, and removed duplicate/invalid script includes for a cleaner Docsify setup.
• Corrected minor grammatical errors and improved phrasing in docs/README.md and other documentation files.
• Enhanced clarity in docs/Getting_Started/Getting_Started_Overview.md and docs/Installation/Troubleshooting_Install.md.
• Adjusted headings/formatting in a few sections for better readability.

Related Issue

N/A

Motivation and Context

• The sidebar had broken links and inconsistent structure, making navigation harder.
• docs/index.html included duplicate Docsify script tags (and a stray closing tag), which can cause Docsify/plugins to load incorrectly.
• Several docs pages had small typos/awkward phrasing that reduced readability.

How Has This Been Tested

• Validated that all _sidebar.md link targets exist in docs/ (local script check).
• No automated tests were run (docs-only change).

Types of changes

• Docs change / refactoring / dependency upgrade

Checklist

• I have read the CONTRIBUTING document.
• My code follows the code style of this project.
• I have checked that my code does not duplicate functionality elsewhere in Caster.
• My code implements all the features I wish to merge in this pull request.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

Maintainer/Reviewer Checklist (self reviewed as low risk)

• Basic functionality has been tested and works as claimed.
• New documentation is clear and complete.
• Code is clear and readable.

[LexiconCode]

Thank you! This looks great!