Switched currency converter to duckduckgo and added Bitcoin to currency list

Fix findx engine

[fix] Force English results in Google when using en-US

Add pronunciaton of searx to README

[fix] Engine fixes

This solves a bug with Yahoo where some results don't specify
a protocol.

[mod] Refactor engine's search language handling

Add match_language function in utils to match any user given
language code with a list of engine's supported languages.

Also add language_aliases dict on each engine to translate
standard language codes into the custom codes used by the engine.

Add findx engine

Add languages supported by either all default general engines or 10 engines.

[fix] Change duckduckgo url to avoid error response

Fix Vim mode on Firefox

Change alpine version to permit ARM and amd64 deployment

[UI] fix custom-select in oscar

Firefox automatically opens a built-in quick search when user
starts typing without selected input and the Vim shortcuts
are not triggered

remove the option of sourcing manage.sh