Rewrite/simplify the install and testing docs

docs/INSTALLATION.md

@@ -1,56 +1,19 @@
 # Installation
 
-## Installing Godot Engine
+The [Godot Engine][godot-engine] is used to run GDScript code.
+The Godot Engine runs on Windows, Linux, macOS, and Android.
+
 
-The GDScript track is built on top of [Godot Engine][godot-engine], which runs on Windows, Linux, macOS, and Android.
-For the moment, the test runner for [working locally][working-locally] requires Linux.
-This track requires Godot version 4.0 or greater.
 
+## Installing Godot Engine
+
+The Godot Engine can be downloaded directly from [the Godot Engine website][godot-engine].
+The download contains a single executable, named with the Godot Engine version.
+This file needs to renamed `godot` and placed in one of the `$PATH` directories.
 After completing the installation, you can verify if the CLI was installed successfully by running this command in a terminal:
 
 ```bash
 godot --version
 ```
 
-## Installing the Exercism GDScript track test runner
-
-You'll need [Godot installed][installation] correctly to use the test runner.
-
-To build and test GDScript scripts for Exercism, Godot will be run in "headless" mode from the CLI.
-These instructions currently require Linux and bash.
-
-### Step 1: Installing the overall test runner infrastructure
-
-To set up for testing, clone [https://github.com/exercism/gdscript-test-runner][gdscript-test-runner] and move its contents to `/opt/test-runner/`:
-
-```sh
-git clone https://github.com/exercism/gdscript-test-runner.git
-sudo mv gdscript-test-runner/ /opt/test-runner/
-```
-
-### Step 2: Downloading the single-exercise test runner script
-
-Assuming you have the `exercism` tool set up and have downloaded at least one GDScript exercise, it should have created a `gdscript` folder under your workspace (as shown by running `exercism configure`) to house the exercises.
-Save [the test runner][test-local-gdscript-solution] in this folder and mark the file executable.
-
-## Running tests
-
-With the installation steps done, you should be able start from any exercise directory (e.g., `~/exercism/gdscript/two-fer`) and run the script (living one level up, in `../`) to test your local solution to that exercise:
-
-```sh
-../test-local-gdscript-solution.sh
-```
-
-[installation]: https://exercism.org/docs/tracks/gdscript/installation
-[gdscript-test-runner]: https://github.com/exercism/gdscript-test-runner
-[test-local-gdscript-solution]: https://raw.githubusercontent.com/exercism/gdscript-test-runner/refs/heads/main/bin/test-local-gdscript-solution.sh
-
-## Using an IDE
-
-To get GDScript syntax highlighting inside an editor like [Visual Studio Code][vscode], you'll need an extension such as [godot-tools][godot-tools] installed plus a running debug server.
-Godot starts this debug server automatically whenever a project is open in its own editor and keeps it running until the project or Godot itself is closed.
-
-[godot-engine]: https://godotengine.org/
-[working-locally]: /docs/using/solving-exercises/working-locally.md
-[vscode]: https://code.visualstudio.com/download
-[godot-tools]: https://open-vsx.org/vscode/item?itemName=geequlim.godot-tools
+This track uses Godot version 4.7.2.

docs/TESTS.md

@@ -1,40 +1,22 @@
 # Tests
 
-## Installing the Exercism GDScript track test runner
-
 You'll need [Godot installed][installation] correctly to use the test runner.
 
-To build and test GDScript scripts for Exercism, Godot will be run in "headless" mode from the CLI.
-These instructions currently require Linux and bash.
-
-### Step 1: Installing the overall test runner infrastructure
+## Running tests
 
-To set up for testing, clone [https://github.com/exercism/gdscript-test-runner][gdscript-test-runner] and move its contents to `/opt/test-runner/`:
+The [test runner][] is used to load and test solutions.
+To run the test runner, download it locally then use `godot` to run the test runner.
+In the future, the test runner will automatically be downloaded alongside exercises when using `exercism download`.
 
-```sh
-git clone https://github.com/exercism/gdscript-test-runner.git
-sudo mkdir -p /opt/
-sudo mv gdscript-test-runner/ /opt/test-runner/
+```bash
+godot --headless -s /path/to/test_runner.gd -- <solution-slug> <path/to/solution>
 ```
 
-### Step 2: Downloading the single-exercise test runner script
-
-Assuming you have the `exercism` tool set up and have downloaded at least one GDScript exercise, it should have created an `exercism/gdscript` folder to house the exercises.
-Save [the test runner][test-local-gdscript-solution] in this folder and mark the file executable, or just create a link to it:
+For example,
 
-```sh
-cd ~/exercism/gdscript # replace with your exercism/gdscript directory
-ln /opt/test-runner/bin/test-local-gdscript-solution.sh
+```bash
 ```
 
-## Running tests
-
-With the installation steps done, you should be able start from any exercise directory (e.g., `~/exercism/gdscript/two-fer`) and run the script (living one level up, in `../`) to test your local solution to that exercise:
-
-```sh
-../test-local-gdscript-solution.sh
-```
 
 [installation]: https://exercism.org/docs/tracks/gdscript/installation
-[gdscript-test-runner]: https://github.com/exercism/gdscript-test-runner
-[test-local-gdscript-solution]: https://raw.githubusercontent.com/exercism/gdscript-test-runner/refs/heads/main/bin/test-local-gdscript-solution.sh
+[test runner]: https://raw.githubusercontent.com/exercism/gdscript-test-runner/refs/heads/main/bin/test_runner.gd