Add CurseForge release workflow

scripts/set_curseforge_env.sh

@@ -0,0 +1,42 @@
+#!/bin/bash
+#
+# Copyright (C) 2011-2021 lishid. All rights reserved.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, version 3.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+# Note that this script is designed for use in GitHub Actions, and is not
+# particularly robust nor configurable. Run from project parent directory.
+
+# Parse Spigot dependency information into major Minecraft versions
+function get_curseforge_minecraft_versions() {
+  versions=$(. ./scripts/get_spigot_versions.sh)
+
+  for version in "${versions[@]}"; do
+    # Parse Minecraft major version
+    version="${version%[.-]"${version#*.*[.-]}"}"
+
+    # Skip already listed versions
+    if [[ "$minecraft_versions" =~ "$version"($|,) ]]; then
+      continue
+    fi
+
+    # Append comma if variable is set, then append version
+    minecraft_versions="${minecraft_versions:+${minecraft_versions},}Minecraft ${version}"
+  done
+
+  echo "${minecraft_versions}"
+}
+
+minecraft_versions=$(get_curseforge_minecraft_versions)
+echo "CURSEFORGE_MINECRAFT_VERSIONS=$minecraft_versions"