I've started a similar project some months ago, however, my idea was to put the crawl- and search-software on a server so that the search engine can be used even on mobile devices, tablets and so on. On server installation could serve all devices in a household or in a small company then.
The software is far away from being ready, esp. the kernel, the distributes search is not really implmented, the last months I had not much time to contribute, however, what is done is available here under an open source license: https://github.com/r10s/gosearch
[1] https://delta.chat/en/2019-05-08-xyiv#the-coming-delta-chat-...