feat: slugify a value

slugify.sh

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+
+KEY=${INPUT_KEY^^}
+CS_VALUE=${INPUT_VALUE:-${!INPUT_KEY}}
+VALUE=${CS_VALUE,,}
+
+slug() {
+  echo "$1" |
+    sed -r 's#refs/[^\/]*/##;s/[^a-zA-Z0-9._]+/-/g;s/^-*//;s/-*$//' |
+    cut -c1-63
+}
+
+slug_url() {
+  echo "$1" |
+    sed -r 's#refs/[^\/]*/##;s/[^a-zA-Z0-9_]+/-/g;s/^-//;s/-$//' |
+    cut -c1-63
+}
+
+{
+  echo "${KEY}=${CS_VALUE}"
+  echo "${KEY}_SLUG=$(slug "$VALUE")"
+  echo "${KEY}_SLUG_CS=$(slug "$CS_VALUE")"
+  echo "${KEY}_SLUG_URL=$(slug_url "$VALUE")"
+  echo "${KEY}_SLUG_URL_CS=$(slug_url "$CS_VALUE")"
+} >>"$GITHUB_ENV"