Best possible preview snippets would be essential when looking for trivial stuff : cant remember exactly how to do sth but knew it once (google does that for the best SO match i think)

Exception messages could be an important thing to focus on. That is the second thing i when search engines matter to me often (support fuzzy search here: abstract away the too concrete stuff but keep the actual message).

It would be great if you would understand versioning of documenations: it always takes me a while to understand if the docs apply to the version i am actually using.