I recently generated a Dash docset from the Vibe.d API docs. Using Dash for OSX or Zeal for Linux/Windows you can quickly search through every function, struct, module, enum, variable and constant in Vibe.d
If you're using Dash you can find it the user contributed section, along with my docset for D's phobos.
Having these docsets on hand really helped me in writing my first Vibe.d app. I hope they can help you as well. It is much faster than digging through the website.
Also Sönke if you notice very occassional massive traffic spikes on the API docs from one IP, that is me downloading every single page of the Vibe.d docs, which is thousands of them. If you have logs you can probably see a spike a couple days ago.