Flatten the module hierarchy

Move Parser and Options up

lib/youplot/options.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+module YouPlot
+  Options = Struct.new(
+    :delimiter,
+    :transpose,
+    :headers,
+    :pass,
+    :output,
+    :fmt,
+    :progressive,
+    :encoding,
+    :color_names,
+    :debug,
+    keyword_init: true
+  )
+end