DOCUMENTATION: Convert old rst files to md files

[Paulaaass]

Description

This pull request addresses the issue #1564 by converting the remaining .rst files to .md files. The original .rst files were deleted in PR #667, and some useful files were missed in the initial conversion. These files have now been carefully converted to Markdown format.

Files converted:

shortcuts.rst to shortcuts.md

netscript\advancedfunctions\autocomplete.rst to netscript\advancedfunctions\autocomplete.md

netscript\advancedfunctions\inject_html.rst to netscript\advancedfunctions\inject_html.md

netscript\netscriptmisc.rst to netscript\netscriptmisc.md

netscript\netscriptscriptarguments.rst to netscript\netscriptscriptarguments.md

netscript\netscripthacknetnodeapi.rst to netscript\netscripthacknetnodeapi.md

Importance of the changes:

Consistency: Converting these files to Markdown ensures that all documentation files follow a uniform format, making it easier for contributors and readers to navigate and understand the documentation.

Readability: Markdown files are more readable and easier to edit, which enhances the overall user experience when accessing the documentation.

Maintainability: A consistent file format simplifies the maintenance and updating process for future documentation changes.

Notes:

Each file was carefully reviewed to ensure that only relevant and useful content was included in the conversion process.
Formatting was updated to be compatible with Markdown syntax.

[catloversg]

Note:

• This PR includes commits from UI: Enhance navigation and accesibility with keyboard tabindex attributes #1914. You need to rebase your branch.
• All mentions of "Netscript 1" and other legacy stuff (e.g., ".ns2") need to be removed. There is no need to mention the difference between "Netscript1" and "Netscript2/NetscriptJS" in these files.
• Some files are empty. Is this PR a WIP one?
• These files should not be in the "advanced" folder.

[d0sboots]

Agreed with what catlover said, although maybe some should be in the advanced folder? Not all of them though.