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/RedHat/MergeConflictMarkers.yml

@@ -0,0 +1,13 @@
+---
+extends: existence
+scope: raw
+level: error
+nonword: true
+link: https://redhat-documentation.github.io/vale-at-red-hat/docs/main/reference-guide/mergeconflictmarkers/
+message: "Do not commit Git merge conflict markers in source code."
+action:
+  name: remove
+tokens:
+  - '^<{7}\s.*$'
+  - '^={7}$'
+  - '^>{7}\s.*$'