So in the Technical documentation page project, does this work as a technical documentation page?
Also, I have a problem, the W3 validator tells me that I need to use h2-h6 elements in every section, what should I do? I think sections look identified already.
Here is a link to what I have done so far:
https://codepen.io/moustafa-ahmed/pen/abvLEVo
That absolutely works as a technical documentation. Your website is functionally similar (passes all the tests) but you personalised it and made it yours. Nice work!
The warnings you get from the W3 validator for the sections needing proper <h2> has to do with accessibility - having a <section> element without all the heading elements will mess with screen readers and cause them to skip over heading levels. It’s good information to know, for sure, but for the scope and purpose of this project I wouldn’t worry too much about it.
Also, it looks like I can run ThisApp! 
Thanks a lot! Appreciate your response.