add setup guide in README

Author: Project516

README.md

@@ -1 +1,67 @@
-# JavaAppTemplate
+# JavaAppTemplate
+
+## Setup
+
+**Requirements**
+
+- **Java JDK**: Java 8 or newer installed and `JAVA_HOME` configured.
+
+**Quick start — Terminal**
+
+Linux / macOS (bash / zsh):
+
+```bash
+# from project root
+./gradlew clean build
+./gradlew run
+```
+
+Windows (PowerShell):
+
+```powershell
+# from project root
+.\gradlew.bat clean build
+.\gradlew.bat run
+```
+
+Windows (CMD):
+
+```cmd
+cd %~dp0
+gradlew.bat clean build
+gradlew.bat run
+```
+
+Notes:
+- `./gradlew run` uses the Gradle `application` plugin (if configured) to run the app.
+- To run the produced JAR directly after building:
+
+```bash
+# replace with the actual jar name in build/libs
+java -jar build/libs/JavaAppTemplate-all.jar
+```
+
+**Run tests**
+
+```bash
+# run tests
+./gradlew test
+```
+
+**Run in Visual Studio Code**
+
+1. Open the project folder in VS Code.
+2. Install the **Java Extension Pack** (provides Language Support, Debugger, Maven/Gradle support).
+3. Use the **Run and Debug** view to create or start a Java launch configuration, or:
+	- Open the built-in Terminal (View → Terminal) and run `./gradlew run` (or `gradlew.bat run` on Windows).
+	- Use the **Gradle Tasks** view (from the sidebar) to run the `run` or `test` tasks.
+
+**Troubleshooting**
+
+- If Gradle complains about Java version, ensure `JAVA_HOME` points to a supported JDK and that `java -version` shows the same.
+- On Windows, prefer PowerShell or Git Bash for the provided scripts; ensure `gradlew.bat` is executable.
+- If you get missing dependency errors, run `./gradlew --refresh-dependencies`.
+
+**Files**
+
+See the main entry point at `src/main/java/dev/project516/JavaAppTemplate/Main.java`.