Add DOI resolver: Library Genesis

[1366613]

Here's sample query from Library Genesis:
http://libgen.gs/scimag/ads.php?doi=10.1063/1.529338

Currently working alternative domains: libgen.li and libgen.lc.

It's very easy to implement.

Also, the whole Library Genesis scientific papers database could be fetched from libgen.rs/dbdumps/scimag.sql.gz to be used in case of an offline query.

[unixfox]

Are those domains working out of the box with Searx?

[1366613]

@unixfox

Are those domains working out of the box with Searx?

What would you exactly mean by 'out of the box' in this case? Like the way searx's current DOI resolvers work?