Add WIP docs tutorial for creating templates

docs/source/gallery/tutorials/templates.py

@@ -0,0 +1,13 @@
+"""
+Creating Classification Diagrams
+==================================
+
+* Create JSON files
+* Add util.classification
+* Add plot.templates file
+
+"""
+#######################################################################################
+# First let's pull in a simple dataset to use throughout these examples:
+#
+from pyrolite.util.synthetic import normal_frame