feat(fabric-server): create fabric-server package

pkgs/fabric-server/generate-lock-nix.bash

@@ -0,0 +1,22 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -i bash -p bash curl jq
+curl https://meta.fabricmc.net/v2/versions/loader/1.18.1/0.13.1/server/json \
+| jq -r '
+  .mainClass,
+  (.libraries[]
+  | .url as $url
+  | .name | split(":") as [$dir, $name, $version]
+  |"\($name)-\($version).zip|\($url)\($dir|sub("\\.";"/";"g"))/\($name)/\($version)/\($name)-\($version).jar"
+  )' \
+| {
+    echo '{'
+    read mainClass;
+    echo "  mainClass = \"$mainClass\";"
+    echo "  libraries = ["
+    while IFS="|" read name url; do
+        hash=$(nix-prefetch-url $url);
+        echo "    { name = \"$name\"; sha256 = \"$hash\"; url = \"$url\"; }"
+    done
+    echo "  ];"
+    echo '}'
+}