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/Cursing.yml

@@ -0,0 +1,15 @@
+extends: existence
+message: "Consider replacing '%s'."
+level: error
+ignorecase: true
+tokens:
+  - shit
+  - piss
+  - fuck
+  - cunt
+  - cocksucker
+  - motherfucker
+  - tits
+  - fart
+  - turd
+  - twat