fixup: feat(patching): initial scaffolding for the patching helper script

hsh-fork-helper.sh

+#! /usr/bin/env bash
+
+# This helper script is supposed to help maintaining our fork with various
+# patches applied.
+
+# Make sure the following problems rather error than just bug out:
+# * always exit with non-zero return value on error
+# * let pipefails exit with non-zero return value
+# * let overwriting files exit with an error too
+# * let usage of unset variables exit with non-zero return value
+set -o errexit -o pipefail -o noclobber -o nounset
+
+help() {
+    script_name=${0##*/}
+    echo "
+$script_name
+HsH patching helper script in ease maintaining H5P versions for which we want to apply a variety of patches.
+Usage: $script_name command
+Commands:
+    * init             sets the original repo from GitHub as a remote (called upstream)
+    * fetch            fetches all changes from upstream into the main branch
+    * apply-patches    create a seperate HsH-themed branch from current version and applies all available patches for it
+    * pack             packs the current version into a zip
+    * help             prints this text.
+
+Omitting the command will automatically invoke help.
+"
+    exit 1
+}
+
+init() {
+    echo ""
+}
+
+fetch() {
+    echo ""
+}
+
+apply_patches() {
+    echo ""
+}
+
+pack() {
+    echo ""
+}
+
+case "$1" in
+    init)
+        init "$2"
+        ;;
+    fetch)
+        fetch "$2"
+        ;;
+    apply-patches)
+        apply_patches "$2"
+        ;;
+    pack)
+        pack "$2"
+        ;;
+    help|*)
+        help
+        ;;
+esac