adds crystals parser code

lib/parser/module_definition.rb

@@ -0,0 +1,15 @@
+module Parser
+  module ModuleDef
+    include Parslet
+    rule(:module_definition) do
+      keyword_module >> module_name >> eol >>
+      ( (keyword_end.absent? >> root_body).repeat()).as(:module_expressions) >> keyword_end >> newline
+    end
+
+    rule(:class_definition) do
+      keyword_class >> module_name >> eol >>
+      ( (keyword_end.absent? >> root_body).repeat()).as(:class_expressions) >> keyword_end >> newline
+    end
+
+  end
+end