tsconfig.json

Used to let TypeScript know what you're doing and get TypeScriptToLua to do what you want

{
    "compilerOptions": {
        "lib": ["es2017"],
        "strict": true
    },
    "types": [],
    "luaTarget": "JIT",
}

Option	Effects	Description
rootDir	File System	The directory where your TypeScript files are
outDir	File System	The directory where Lua files will go (same structure as rootDir)
luaTarget	Output Lua	Can be jit, 5.3, 5.2 or 5.1
lib	Typings	Describes, to TypeScript, what environmental definitions exist
types	Typings	A list of paths to the declarations you wish to use
strict	Typings	Enables a collection of strict rules