I noticed that OpenComputers' manual are written in Markdown format, and docs can be added by external sources like ExtraCells2(see https://github.com/ExtraCells/ExtraCells2/tree/rv6-1.12/src/main/resources/assets/extracells/doc), so it should be possible and easy to add LostUser's README.md to OpenComputers' manual.

By doing so, I can view the docs without the needs of opening a browser page and switching back and forth, definitely will be a smoother gameplay

Very nice idea! Thank you for noticing me this. I will think to implement it.

I tried to research where i could find syntax rules for those doc files. If you know, tell me.
Also, this would be hard to implement if OC not support things like tables.

OC doc parsing is defined in this package: li.cil.oc.client.renderer.markdown, and you can find all supported markdown syntaxs in its sub-package.

There are two markup formats for OC doc, defined here, but both of them are for Markdown.

A bad news is that, yes, it does not support table, only basic syntaxes can be parsed, some of them are defined here.

Another bad news is that it will be hard support table by ourselves, because there's no commits related to table support for OC, not even after Markdown doc is split into MarkdownManual by some other authors. We have no reference implementation or workaround for it whatsoever

Theoretically, i could "disassemble" table to bullet points, but this would require me to write my own "unparser". And i will need to do the same for many other unsupported formattings.

Considering LostUser is very unpopular, I believe there is no potential users of this ingame gui except you 😁
For you to know - there was no mentions of someone write on LostUser something more complicated than "move 5 times forward, use and go back".