Add icons and highlight.js to project

This commit includes the addition of a new toolbox icon in both .ico and .png formats, updating the resource file to reference the new icon. In addition, numerous highlight.js files and styles have been integrated into the project, enhancing syntax highlighting capabilities. Existing file references in 'out_embed/all.hpp' have been updated accordingly.Add new highlighting styles and GitHub CSS to project

Introduced two new image styles, "brown-papersq" and "pojoaque", for highlighting. Additionally, embedded GitHub's CSS files as header files in the `saucer::embedded` namespace to enhance syntax highlighting features. These changes aim to improve the visual styling and customization options for code presentation.

res/highlight/README.md

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+# Highlight.js CDN Assets
+
+[![install size](https://packagephobia.now.sh/badge?p=highlight.js)](https://packagephobia.now.sh/result?p=highlight.js)
+
+**This package contains only the CDN build assets of highlight.js.**
+
+This may be what you want if you'd like to install the pre-built distributable highlight.js client-side assets via NPM. If you're wanting to use highlight.js mainly on the server-side you likely want the [highlight.js][1] package instead.
+
+To access these files via CDN:<br>
+https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@latest/build/
+
+**If you just want a single .js file with the common languages built-in:
+<https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@latest/build/highlight.min.js>**
+
+---
+
+## Highlight.js
+
+Highlight.js is a syntax highlighter written in JavaScript. It works in
+the browser as well as on the server. It works with pretty much any
+markup, doesn’t depend on any framework, and has automatic language
+detection.
+
+If you'd like to read the full README:<br>
+<https://github.com/highlightjs/highlight.js/blob/main/README.md>
+
+## License
+
+Highlight.js is released under the BSD License. See [LICENSE][7] file
+for details.
+
+## Links
+
+The official site for the library is at <https://highlightjs.org/>.
+
+The Github project may be found at: <https://github.com/highlightjs/highlight.js>
+
+Further in-depth documentation for the API and other topics is at
+<http://highlightjs.readthedocs.io/>.
+
+A list of the Core Team and contributors can be found in the [CONTRIBUTORS.md][8] file.
+
+[1]: https://www.npmjs.com/package/highlight.js
+[7]: https://github.com/highlightjs/highlight.js/blob/main/LICENSE
+[8]: https://github.com/highlightjs/highlight.js/blob/main/CONTRIBUTORS.md