add submodule

Author: saspivey98

.gitmodules

@@ -271,3 +271,6 @@
 [submodule "addons/rapidjson/module"]
 	path = addons/rapidjson/module
 	url = https://github.com/saspivey98/rapidjson-definitions.git
+[submodule "addons/luasql/module"]
+	path = addons/luasql/module
+	url = https://github.com/saspivey98/luasql-definitions

addons/luasql/info.json

@@ -0,0 +1,5 @@
+{
+  "$schema": "https://raw.githubusercontent.com/LuaLS/LLS-Addons/main/schemas/addon_info.schema.json",
+  "name": "LuaSQL",
+  "description": "LuaSQL is a simple interface from Lua to a DBMS."
+}