automate vanilla registry extraction on linux

* Adding a simple check if someone has read the readme

* semi automate the registeries generation. still requires manually downloading server.jar for eula purposes

* The mods have spoken: no spelling mistakes allowed.

* mention extract_registries script in readme

---------

Co-authored-by: p2r3 <41925384+p2r3@users.noreply.github.com>

extract_registries.sh

@@ -0,0 +1,73 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+REQUIRED_MAJOR=21
+SERVER_JAR="${SERVER_JAR:-server.jar}"
+NOTCHIAN_DIR="notchian"
+JS_RUNTIME=""
+
+get_java_version() {
+  java -version 2>&1 | awk -F[\".] '/version/ {print $2}'
+}
+
+check_java() {
+  if ! command -v java >/dev/null 2>&1; then
+    echo "Java not found in PATH."
+    exit 1
+  fi
+
+  local major
+  major="$(get_java_version)"
+
+  if (( major < REQUIRED_MAJOR )); then
+    echo "Java $REQUIRED_MAJOR or newer required, but found Java $major."
+    exit 1
+  fi
+}
+
+prepare_notchian_dir() {
+  if [[ ! -d "$NOTCHIAN_DIR" ]]; then
+    echo "Creating $NOTCHIAN_DIR directory..."
+    mkdir -p "$NOTCHIAN_DIR"
+  fi
+  cd "$NOTCHIAN_DIR"
+}
+
+dump_registries() {
+  if [[ ! -f "$SERVER_JAR" ]]; then
+    echo "No server.jar found (looked for $SERVER_JAR)."
+	echo "Please download the server.jar from https://www.minecraft.net/en-us/download/server"
+	echo "and place it in the notchian directory."
+    exit 1
+  fi
+
+  java -DbundlerMainClass="net.minecraft.data.Main" -jar "$SERVER_JAR" --all
+}
+
+detect_js_runtime() {
+  if command -v node >/dev/null 2>&1; then
+    JS_RUNTIME="node"
+  elif command -v bun >/dev/null 2>&1; then
+    JS_RUNTIME="bun"
+  elif command -v deno >/dev/null 2>&1; then
+    JS_RUNTIME="deno run"
+  else
+    echo "No JavaScript runtime found (Node.js, Bun, or Deno)."
+    exit 1
+  fi
+}
+
+run_js_script() {
+  local script="$1"
+  if [[ -z "$JS_RUNTIME" ]]; then
+    detect_js_runtime
+  fi
+  echo "Running $script with $JS_RUNTIME..."
+  $JS_RUNTIME "$script"
+}
+
+check_java
+prepare_notchian_dir
+dump_registries
+run_js_script "../build_registries.js"
+echo "Registry dump and processing complete."