You are welcome to contribute to the KDE TechBase wiki. In order to keep a high quality of the articles there are some guidelines you should follow.
The KDE TechBase wiki is meant to contain technical information all around KDE, for instance
The KDE TechBase wiki uses subpages. Take a quick look at the article about the Help:Wiki Structure. In short: Do not randomly add toplevel pages.
It is possible to translate KDE TechBase articles into other languages. Read the article about Help:Wiki Translation for further details.
You want to add new content. To keep high quality, please create the article in your userpage first (e.g. User:foo/My Acticle). Once it is ready, discuss the article with other developers and proof-read it. Finally, if a location is found, move the page.
After moving the page please add yourself to the watch list by clicking the Watch register. You will get a notice by mail whenever the page changes.