[fix] add more description on possible search tpyes

searx/engines/mediawiki.py

     '&format=json'\
     '&sroffset={offset}'\
     '&srlimit={limit}'\
-    '&srwhat={searchtype}'  # search for a near match in the title
+    '&srwhat={searchtype}'
 
 
 # do search-request

searx/settings.yml

     categories : it
     base_url : https://directory.fsf.org/
     number_of_results : 5
+# what part of a page matches the query string: title, text, nearmatch
+# title - query matches title, text - query matches the text of page, nearmatch - nearmatch in title
     search_type : title
     timeout : 5.0
     disabled : True