[vale] Add some vale styles and an ini file

vale/.vale-styles/Microsoft/DateOrder.yml

@@ -0,0 +1,8 @@
+extends: existence
+message: "Always spell out the name of the month."
+link: https://docs.microsoft.com/en-us/style-guide/numbers#numbers-in-dates
+ignorecase: true
+level: error
+nonword: true
+tokens:
+  - '\b\d{1,2}/\d{1,2}/(?:\d{4}|\d{2})\b'