Merge pull request #2372 from dalf/remove-broken-engines

[remove] remove searchcode_doc and twitter

searx/settings.yml

@@ -694,10 +694,6 @@ engines:
     engine : stackoverflow
     shortcut : st
 
-  - name : searchcode doc
-    engine : searchcode_doc
-    shortcut : scd
-
   - name : searchcode code
     engine : searchcode_code
     shortcut : scc
@@ -764,10 +760,6 @@ engines:
     categories : onions
     shortcut : tch
 
-  - name : twitter
-    engine : twitter
-    shortcut : tw
-
 # maybe in a fun category
 #  - name : uncyclopedia
 #    engine : mediawiki