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/proselint/Oxymorons.yml

@@ -0,0 +1,22 @@
+extends: existence
+message: "'%s' is an oxymoron."
+ignorecase: true
+level: error
+tokens:
+  - amateur expert
+  - increasingly less
+  - advancing backwards
+  - alludes explicitly to
+  - explicitly alludes to
+  - totally obsolescent
+  - completely obsolescent
+  - generally always
+  - usually always
+  - increasingly less
+  - build down
+  - conspicuous absence
+  - exact estimate
+  - found missing
+  - intense apathy
+  - mandatory choice
+  - organized mess