docs(user): public instances, fix Searxes@Danwin entry

fixes: https://github.com/asciimoo/searx/issues/1770

This is not Searx at all. This is Meta-Searx with other engines.

See https://github.com/asciimoo/searx/issues/1770#issuecomment-570776655



Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>