Improved syntax highlighting

[pygrum]

Changes

Previously, Console used the cobra.Command usage rather than the operand for syntax highlighting. This prevented highlights from being made with commands that had usages with positional arguments, e.g. exit [code].

This change now allows highlighting for such commands, and doesn't affect commands with single word usages - they still highlight.

Example / test script:

package main

import (
        "os"
        "fmt"
        "github.com/reeflective/console"
        "github.com/spf13/cobra"
)

func cmds() *cobra.Command {
        rootCmd := &cobra.Command{}
        exitCmd := &cobra.Command{
                Use: "exit [code]",
                Short: "exit the application",
                Run: func(cmd *cobra.Command, args []string) {
                        os.Exit(0)
                },
        }
        hwCmd := &cobra.Command{
                Use: "hw",
                Short: "print hello world",
                Run: func(cmd *cobra.Command, args []string) {
                        fmt.Println("Hello, World!")
                },
        }
        rootCmd.AddCommand(exitCmd, hwCmd)
        return rootCmd
}

func main(){
        app := console.New("app")
        menu := app.ActiveMenu()
        menu.SetCommands(cmds)
        app.Start()
}

[maxlandon]

Thanks a lot for this ! Running the workflows and merging !