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/LGBTOffensive.yml

@@ -0,0 +1,13 @@
+extends: existence
+message: "'%s' is offensive. Remove it or consider the context."
+ignorecase: true
+tokens:
+  - fag
+  - faggot
+  - dyke
+  - sodomite
+  - homosexual agenda
+  - gay agenda
+  - transvestite
+  - homosexual lifestyle
+  - gay lifestyle