Minor luacheck fixes (#1)

.github/workflows/check-release.yml

@@ -0,0 +1,11 @@
+on: [push, pull_request]
+name: Check & Release
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+      - name: lint
+        uses: Roang-zero1/factorio-mod-luacheck@master
+        with:
+          luacheckrc_url: https://raw.githubusercontent.com/BlockySurvival/irc2/master/.luacheckrc

.luacheckrc

@@ -2,7 +2,8 @@
 allow_defined_top = true
 
 read_globals = {
-	"minetest",
+	"minetest", "core",
+	"cloaking",
 }
 
 exclude_files = {