Codeblock language support is insufficient

[temeddix]

The docs say that supported languages are those of Shiki.

https://github.com/svelteness/kit-docs/blob/88fa1aec6a366a2e1896b7387510e69d5cb91d28/packages/kit-docs/src/node/markdown-plugin/parser/plugins/shiki-plugin.ts#L7

However, not all languages from Shiki are included in this library.

This results in error when writing other languages, such as Python in markdown codeblocks.