[vale] Add some vale styles and an ini file

vale/.vale-styles/Google/DateFormat.yml

@@ -0,0 +1,9 @@
+extends: existence
+message: "Use 'July 31, 2016' format, not '%s'."
+link: 'https://developers.google.com/style/dates-times'
+ignorecase: true
+level: error
+nonword: true
+tokens:
+  - '\d{1,2}(?:\.|/)\d{1,2}(?:\.|/)\d{4}'
+  - '\d{1,2} (?:Jan(?:uary)?|Feb(?:ruary)?|Mar(?:ch)?|Apr(?:il)|May|Jun(?:e)|Jul(?:y)|Aug(?:ust)|Sep(?:tember)?|Oct(?:ober)|Nov(?:ember)?|Dec(?:ember)?) \d{4}'