If it's unavailable at the ipfs link, you can also find it here.
It doesn't work very well yet - one word searches generally work best. The search is powered by lunr.js, and the search index is built by scraping a public searx instance, which itself is aggregating results from major search providers.
(search source, scraper source)
IPFS is an open source project developed by the team at Interplanetary Networks and many contributors from the open source community.