Rename count -> count_values

lib/uplot/plot.rb

@@ -11,7 +11,7 @@ module Uplot
       headers = data.headers
       series = data.series
       if count
-        series = Preprocessing.count(series[0])
+        series = Preprocessing.count_values(series[0])
         params.title = headers[0] if headers
       end
       params.title ||= headers[1] if headers

lib/uplot/preprocessing.rb

@@ -71,7 +71,7 @@ module Uplot
       end
     end
 
-    def count(arr)
+    def count_values(arr)
       # tally was added in Ruby 2.7
       if Enumerable.method_defined? :tally
         arr.tally