chore: Add command desc & color commands (#2013)

* Add link & Color sub-commands

* Color sub-commands for unix-like OS

* Remove useless code

* Remove redundant dependency

tools/goctl/cmd/usage.go

@@ -0,0 +1,60 @@
+package cmd
+
+import (
+	"fmt"
+	"runtime"
+
+	"github.com/logrusorgru/aurora"
+	"github.com/zeromicro/go-zero/tools/goctl/vars"
+)
+
+var colorRender = []func(v interface{}) string{
+	func(v interface{}) string {
+		return aurora.BrightRed(v).String()
+	},
+	func(v interface{}) string {
+		return aurora.BrightGreen(v).String()
+	},
+	func(v interface{}) string {
+		return aurora.BrightYellow(v).String()
+	},
+	func(v interface{}) string {
+		return aurora.BrightBlue(v).String()
+	},
+	func(v interface{}) string {
+		return aurora.BrightMagenta(v).String()
+	},
+	func(v interface{}) string {
+		return aurora.BrightCyan(v).String()
+	},
+}
+
+func blue(s string) string {
+	if runtime.GOOS == vars.OsWindows {
+		return s
+	}
+
+	return aurora.BrightBlue(s).String()
+}
+
+func green(s string) string {
+	if runtime.GOOS == vars.OsWindows {
+		return s
+	}
+
+	return aurora.BrightGreen(s).String()
+}
+
+func rainbow(s string) string {
+	if runtime.GOOS == vars.OsWindows {
+		return s
+	}
+	s0 := s[0]
+	return colorRender[int(s0)%(len(colorRender)-1)](s)
+}
+
+// rpadx adds padding to the right of a string.
+func rpadx(s string, padding int) string {
+	template := fmt.Sprintf("%%-%ds", padding)
+	return rainbow(fmt.Sprintf(template, s))
+}