What is the best way to write manuals?

Question

Text editors

I am actively studying in the direction of "Applied Mathematics and Informatics", and I also grab information from the Internet.
There is a desire to write down everything learned not only in the head, but also in the computer. In the long term, it would be nice to make a website out of the accumulated knowledge (and transfer the acquired knowledge, and practice in the DBMS with site building)
From what I know, there are several options for recording my knowledge (I want the design, so I don’t consider a simple * .txt ):

1. Office Word
   
2. HTML5 (XML? XSL?)
   
3. Markdown (Github Flavored Markdown?)
   
4. TeX (and its extensions)
   

I usually use headings of different levels, multi-level lists and color tags for markup. Well, you have to drive in the formulas.
Actually, if I only know Word, will I stop there, or is there something more delicious?

Answer 1

Word is not for programmers,
Markdown is best, but there are also LaTex fans a, xs only, except for formulas, for which they love it