Of course it has. I used it a lot. When you type a word in the search bar, you have a tooltip with "containing...". And when you click on it, it searches within page.Does wiki have "search within page" feature anywhere? I was not aware of such thing.
If you mean browser's built-in search, it doesn't allow searching inside collapsed sections. Recetnly a lot of content in wiki was moved into collapsed blocks, and this is annoying like hell, because to find text on page you have to expand everything manually first. This is especially frustrating when you use global wiki search, it leads to the page with a huge list of events (showing you relevant text fragment but not saying what event does it belong to), and now you need to click through all events until you find one you were searching for. As a result now I prefer searching in game files instead of using wiki.
I didn't meant searching with ctrl-F on the browser. The "containing" search is broken.