Ruby: Add require_relative keyword

rc/filetype/ruby.kak

@@ -90,7 +90,7 @@ evaluate-commands %sh{
     keywords="${keywords}|rescue|retry|return|self|super|then|true|undef|unless|until|when|while|yield"
     attributes="attr_reader|attr_writer|attr_accessor"
     values="false|true|nil"
-    meta="require|include|extend"
+    meta="require|require_relative|include|extend"
 
     # Add the language's grammar to the static completion list
     printf %s\\n "declare-option str-list ruby_static_words ${keywords} ${attributes} ${values} ${meta}" | tr '|' ' '