correct plugin name
correct plugin name

file:a/setup.py -> file:b/setup.py
--- a/setup.py
+++ b/setup.py
@@ -25,7 +25,7 @@
 	entry_points=\
 	"""
         [ckan.plugins]
-	datagm=ckanext.exampletheme:ExampleThemePlugin
+	exampletheme=ckanext.exampletheme:ExampleThemePlugin
 
         [ckan.forms]
         example_form = ckanext.exampletheme.package_form:get_example_fieldset