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/collate-output.tmpl

@@ -0,0 +1,66 @@
+{{- /* See https://github.com/errata-ai/vale/issues/614 */ -}}
+{{- /* See https://vale.sh/manual/output/ */ -}}
+
+{{- /* Keep track of our various counts */ -}}
+
+{{- $e := 0 -}}
+{{- $w := 0 -}}
+{{- $s := 0 -}}
+{{- $f := 0 -}}
+
+{{- /* Range over the linted files */ -}}
+
+{{- range .Files}}
+{{$table := newTable true}}
+
+{{- $f = add1 $f -}}
+{{- .Path | underline | indent 1 -}}
+{{- "\n" -}}
+
+{{- $msgToLoc := dict -}}
+{{- $msgToLvl := dict -}}
+{{- $msgToChk := dict -}}
+
+{{- /* Range over the file's alerts */ -}}
+
+{{- range .Alerts -}}
+
+{{- $error := "" -}}
+{{- if eq .Severity "error" -}}
+    {{- $error = .Severity | red -}}
+    {{- $e = add1 $e  -}}
+{{- else if eq .Severity "warning" -}}
+    {{- $error = .Severity | yellow -}}
+    {{- $w = add1 $w -}}
+{{- else -}}
+    {{- $error = .Severity | blue -}}
+    {{- $s = add1 $s -}}
+{{- end}}
+
+{{- $loc := printf "%d:%d" .Line (index .Span 0) -}}
+
+{{- $locations := get $msgToLoc .Message -}}
+
+{{- $_ := set $msgToLoc .Message (cat $locations $loc) -}}
+{{- $_ := set $msgToLvl .Message $error -}}
+{{- $_ := set $msgToChk .Message .Check -}}
+
+{{end -}}
+
+{{- range keys $msgToLoc -}}
+
+{{- $msg := . -}}
+{{- $loc := trimPrefix "," ((splitList " " (get $msgToLoc $msg)) | join ",") -}}
+{{- $lvl := get $msgToLvl $msg -}}
+{{- $chk := get $msgToChk $msg -}}
+
+{{- $row := list $loc $lvl $msg $chk | toStrings -}}
+{{- $table = addRow $table $row -}}
+
+{{end -}}
+
+{{- $table = renderTable $table -}}
+
+{{end}}
+
+{{- $e}} {{"errors" | red}}, {{$w}} {{"warnings" | yellow}} and {{$s}} {{"suggestions" | blue}} in {{$f}} {{$f | int | plural "file" "files"}}.