Get minisearch.js to cdnjs

[mortenpi]

I noticed it currently comes from jsdelivr, but it would be nice if we'd have them all on one CDN. A starting point would probably to open a library request on cdnjs.

cc @Hetarth02

[shravanngoswamii]

Opened a request on cdnjs: cdnjs/packages#1822

[fingolfin]

Opened a PR for cdnjs: cdnjs/packages#2074