[API] Generator: Avoid duplicating docs when value included in params and parts

Author: picandocodigo

elasticsearch-api/utils/thor/templates/_documentation_top.erb

@@ -12,7 +12,7 @@
 <%- end -%><%# Body -%>
 <%# URL parameters -%>
 <%- @params.each do |name, info| -%>
-  <%= docs_helper(name, info) -%>
+  <%= docs_helper(name, info) unless (!@parts.empty? && @parts.keys.include?(name)) -%>
 <%- end -%>
 # @option arguments [Hash] :headers Custom HTTP headers
 <%- if @spec['body'] -%>