chore: Add Readme (#1)

Author: dido18

README.md

@@ -0,0 +1,123 @@
+# go-updater
+
+A cross-platform updater library for Go applications.
+On Linux and macOS, it replaces the executable (or .app for macOS) and launches the new version, while on Windows, it runs the installer with the required privileges.
+
+## Installation
+
+```bash
+go get github.com/arduino/go-updater
+```
+
+## Quick Start
+
+### 1. Basic Example
+
+Here's a simple example of how to integrate auto-updates into your Go application.
+
+Add a `version` variable in the main package. Note that this variable will be overwritten during the build process through ldflags flag.
+
+```go
+package main
+
+import (
+    "fmt"
+    "log"
+    "os"
+    
+    "github.com/arduino/go-updater/updater"
+    "github.com/arduino/go-updater/releaser"
+)
+
+var version = "0.0.0" 
+
+func main() {
+    // Your current application version
+    currentVersion := releaser.Version(version)
+    
+    // Create HTTP client for your update server
+    // The base URL should point to the parent directory containing platform-specific folders
+    // The client will automatically discover the correct manifest.json based on the current platform
+    // e.g., running on Linux will look for: https://releases.example.com/path/to/release/linux-amd64.json
+    client := releaser.NewClient("https://releases.example.com/", "path/to/release/")
+    
+    fmt.Println("Checking for updates...")
+    executablePath, err := os.Executable()
+	if err != nil {
+		panic("could not get executable path")
+	}
+    confirmUpdate := func(current, target releaser.Version) bool {
+       return true 
+    }
+    err := updater.CheckForUpdates(
+        executablePath,                    // Path to current executable
+        currentVersion,                    // Current version
+        client,                            // HTTP releaser client
+        confirmUpdate,                     // Auto-confirm updates
+    )
+    if err != nil {
+        panic(err)
+    }
+
+    // Note: If an update was found and applied, the application will be restarted
+    // with the new version and the code below will never be executed.
+    // Your application logic should be placed here only for cases where:
+    // - No update was available (err == nil)
+    // - Update check failed (e.g., error fetching the release)
+    // - User declined the update (err == nil)
+}
+```
+
+
+### 2. Build Your Application
+
+Build your application with a specific version by following these requirements:
+- Use the LDFLAGS `-X` flag to set the version at build time
+- Include the version in the output filename (this is mandatory for the releaser tool to function correctly)
+```bash
+GOOS=linux GOARCH=amd64 go build -o myapp-linux-amd64-1.0.0  -ldflags="-X 'main.version=1.0.0'" ./cmd/myapp
+```
+
+### 3. Create Release Manifest
+
+```bash
+go run github.com/arduino/go-updater/cmd/releaser ./myapp-linux-amd64-1.0.0  1.0.0  -platform linux-amd64   -o ./releases/
+
+Release created successfully!
+{
+  "name": "myapp-linux-amd64-1.0.0",
+  "version": "1.0.0",
+  "sha256": "6238F9cnMS8ete3kfDnD9Yk7iDFMWLBX31HXHmii734="
+}
+```
+
+where:
+ - `name` is the name of the executable/archive
+ - `version` is the version of the release
+ - `sha256` is the sha256 of the executable/archive
+
+### 4. Server Setup
+
+Set up an HTTP server to serve your releases. The updater expects this structure where each platform has its own json file:
+
+```
+https://releases.example.com/                    <- Base URL used in NewClient()
+├── /path/to/release/                    
+   ├── myapp-linux-amd64-1.0.0.tar.gz            <- Actual executable/archive
+   ├── myapp-windows-1.0.0-installer.exe
+   ├── myapp-darwin-1.0.0.zip
+   |
+   └── darwin-amd64.json
+   └── linux-amd64.json                          <- Platform manifest 
+   └── windows-amd64.json
+```
+
+## License
+
+This software is released under the GNU General Public License version 3. See the [LICENSE](LICENSE) file for complete details.
+
+For commercial licensing options, please contact license@arduino.cc.
+
+---
+
+Made with ❤️ by [Arduino](https://www.arduino.cc/)

updater/updater.go

@@ -45,7 +45,7 @@ func CheckForUpdates(targetPath string, current releaser.Version, client *releas
 	if err := execApp(restartPath); err != nil {
 		return fmt.Errorf("update applied, but failed to restart application: %w", err)
 	}
-	// TODO: allow to define custom "exit" code to be used in the wail app runtime.quit()
+	// TODO: allow to define custom "exit"
 	os.Exit(0)
 	return nil
 }