Study again search libraries

[postb99]

According to https://github.com/stars/McShelby/lists/web-development

Requirements:

• search index must be buildable by running hugo only. No shell/batch/python nor node/npm

• must support "a major amout" (whatever that is ;-) ) of supported languages by the theme

• must run offline - no calls to extrenal web resources outside of the public folder

• must run from the file system (this is usually not a problem if the other requirements are met)

• https://github.com/CloudCannon/pagefind

• https://github.com/lucaong/minisearch

• https://github.com/weixsong/elasticlunr.js as abandoned as Lunr...

• https://github.com/nextapps-de/flexsearch

• https://github.com/krisk/Fuse - but has languages support issues