Add deprecation for headers and lead-mktg

Author: tobiasahlin

deprecations.js

@@ -5,6 +5,14 @@
  */
 const versionDeprecations = {
   '17.0.0': [
+    {
+      selectors: [
+          '.h000-mktg',
+          '.h00-mktg',
+          '.lead-mktg'
+      ],
+      message: `This selector is deprecated, please refer to the Marketing Typography documentation.`
+    },
     {
       selectors: ['.bg-shade-gradient'],
       message: `This selector is deprecated, please use "color-bg-secondary" instead of "bg-shade-gradient".`