Add example

README.md

@@ -15,6 +15,7 @@ TODO.
 
 * Simple API.
 * Easy to integrate.
+* Builtin `help` and `version` commands.
 * Clean and tested code.
 * Dependency-free.
 
@@ -28,7 +29,42 @@ go get github.com/cristalhq/acmd
 
 ## Example
 
-TODO
+```
+cmds := []acmd.Command{
+	{
+		Name:        "now",
+		Description: "prints current time",
+		Do: func(ctx context.Context, args []string) error {
+			fmt.Printf("now: %s\n", now.Format("15:04:05"))
+			return nil
+		},
+	},
+	{
+		Name:        "status",
+		Description: "prints status of the system",
+		Do: func(ctx context.Context, args []string) error {
+			// do something with ctx :)
+			return nil
+		},
+	},
+}
+
+// all the acmd.Config fields are optional
+r := acmd.RunnerOf(cmds, acmd.Config{
+	AppName:        "acmd-example",
+	AppDescription: "Example of acmd package",
+	Version:        "the best v0.x.y",
+	Context:        nil,
+	Args:           []string{"now"},
+	Usage:          nil,
+})
+
+if err := r.Run(); err != nil {
+	panic(err)
+}
+```
+
+Also see examples: [examples_test.go](https://github.com/cristalhq/acmd/blob/main/example_test.go).
 
 ## Documentation
 

example_test.go

@@ -0,0 +1,55 @@
+package acmd_test
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"time"
+
+	"github.com/cristalhq/acmd"
+)
+
+func ExampleRunner() {
+	const format = "15:04:05"
+	now, _ := time.Parse("15:04:05", "10:20:30")
+
+	cmds := []acmd.Command{
+		{
+			Name:        "now",
+			Description: "prints current time",
+			Do: func(ctx context.Context, args []string) error {
+				fmt.Printf("now: %s\n", now.Format(format))
+				return nil
+			},
+		},
+		{
+			Name:        "status",
+			Description: "prints status of the system",
+			Do: func(ctx context.Context, args []string) error {
+				req, _ := http.NewRequestWithContext(ctx, http.MethodGet, "https://www.githubstatus.com/", http.NoBody)
+				resp, err := http.DefaultClient.Do(req)
+				if err != nil {
+					return err
+				}
+				defer resp.Body.Close()
+				fmt.Print()
+				return nil
+			},
+		},
+	}
+
+	r := acmd.RunnerOf(cmds, acmd.Config{
+		AppName:        "acmd-example",
+		AppDescription: "Example of acmd package",
+		Version:        "the best v0.x.y",
+		Context:        nil,
+		Args:           []string{"now"},
+		Usage:          nil,
+	})
+
+	if err := r.Run(); err != nil {
+		panic(err)
+	}
+
+	// Output: now: 10:20:30
+}