Minor improvements for tasks description

help.go

@@ -0,0 +1,33 @@
+package task
+
+import (
+	"fmt"
+	"os"
+	"sort"
+	"text/tabwriter"
+)
+
+func printExistingTasksHelp() {
+	tasks := tasksWithDesc()
+	if len(tasks) == 0 {
+		return
+	}
+	fmt.Println("Available tasks for this project:")
+
+	// Format in tab-separated columns with a tab stop of 8.
+	w := tabwriter.NewWriter(os.Stdout, 0, 8, 0, '\t', 0)
+	for _, task := range tasks {
+		fmt.Fprintln(w, fmt.Sprintf("- %s:\t%s", task, Tasks[task].Desc))
+	}
+	w.Flush()
+}
+
+func tasksWithDesc() (tasks []string) {
+	for name, task := range Tasks {
+		if task.Desc != "" {
+			tasks = append(tasks, name)
+		}
+	}
+	sort.Strings(tasks)
+	return
+}