Enable vale for prose linting (#3)

* Enable vale in CI

* Add vale config

* Tweak vale

* Update config

* Update .gitignore

* Switch back

* Rename CI

* Add badges

* Tidy up CI

* Change image

* Configure vale

* Delint

* Update README

.github/styles/Google/Latin.yml

@@ -0,0 +1,11 @@
+extends: substitution
+message: "Use '%s' instead of '%s'."
+link: 'https://developers.google.com/style/abbreviations'
+ignorecase: true
+level: error
+nonword: true
+action:
+  name: replace
+swap:
+  '\b(?:eg|e\.g\.)(?=[\s,;])': for example
+  '\b(?:ie|i\.e\.)(?=[\s,;])': that is