Use .rbxl for tests (roblox-ts#2521)

Author: osyrisrblx

.gitignore

@@ -9,6 +9,6 @@ out
 .vscode/launch.json
 .vscode/settings.json
 
-/tests/*.rbxlx
-/tests/*.rbxlx.lock
+/tests/*.rbxl
+/tests/*.rbxl.lock
 /tests/include

CONTRIBUTING.md

@@ -53,14 +53,14 @@ It is not necessary to run the "devlink" script again.
 Effectively, this folder is a tiny **roblox-ts** game. Testing process is as follows:
 
 1. Compile tests project to create a `/tests/out` folder containing `.lua` files
-2. Use `rojo build` to create `/tests/test.rbxlx`
-3. Use `run-in-roblox` to open studio and execute the tests
+2. Use `rojo build` to create `/tests/test.rbxl`
+3. Use `lune` to execute the tests
 
 You can run this process yourself if you have Roblox Studio and [foreman](https://github.com/Roblox/foreman) installed. (Only works on Windows and MacOS)
 
 ```sh
-# install rojo + run-in-roblox
+# install rojo + lune
 foreman install
-# Compile tests, build .rbxlx, run with run-in-roblox
+# Compile tests, build .rbxl, run with lune
 npm test
 ```

package.json

@@ -19,10 +19,10 @@
 		"update-test-types": "cd tests && npm install github:roblox-ts/compiler-types @rbxts/types@latest && npm install",
 		"test": "npm run build && npm run test-compile && npm run test-rojo && npm run test-run",
 		"test-compile": "nyc mocha --timeout 0 --recursive out/CLI/test.js",
-		"test-rojo": "rojo build tests -o ./tests/test.rbxlx",
-		"test-run": "lune ./tests/runLuneTests.lua ./tests/test.rbxlx",
+		"test-rojo": "rojo build tests -o ./tests/test.rbxl",
+		"test-run": "lune ./tests/runLuneTests.lua ./tests/test.rbxl",
 		"test-roblox": "npm run build && npm run test-compile && npm run test-rojo && npm run run-in-roblox",
-		"run-in-roblox": "run-in-roblox --place ./tests/test.rbxlx --script ./tests/out/main.server.lua"
+		"run-in-roblox": "run-in-roblox --place ./tests/test.rbxl --script ./tests/out/main.server.lua"
 	},
 	"nyc": {
 		"all": true,