Fix help output

[mizunashi-mana]

I fixed help output!
Thanks.

Now

$ gitbook help
    build [book] [output]    build a book
        --format     Format to build to (Default is website; Values are website, json, ebook)
        --log    Minimum log level to display (Default is info; Values are debug, info, warn, error, disabled)

    pdf [book] [output]      build a book to pdf
        --log    Minimum log level to display (Default is info; Values are debug, info, warn, error, disabled)

    epub [book] [output]     build a book to epub
        --log    Minimum log level to display (Default is info; Values are debug, info, warn, error, disabled)

    mobi [book] [output]     build a book to mobi
        --log    Minimum log level to display (Default is info; Values are debug, info, warn, error, disabled)

    serve [book]     Build then serve a gitbook from a directory
        --port   Port for server to listen on (Default is 4000)
        --lrport     Port for livereload server to listen on (Default is 35729)
        --watch      Enable/disable file watcher (Default is true)
        --format     Format to build to (Default is website; Values are website, json, ebook)
        --log    Minimum log level to display (Default is info; Values are debug, info, warn, error, disabled)

    install [book]   install plugins dependencies

    init [directory]     create files and folders based on contents of SUMMARY.md

Fixed

$ gitbook help
    build [book] [output]       build a book
        --format                Format to build to (Default is website; Values are website, json, ebook)
        --log                   Minimum log level to display (Default is info; Values are debug, info, warn, error, disabled)

    pdf [book] [output]         build a book to pdf
        --log                   Minimum log level to display (Default is info; Values are debug, info, warn, error, disabled)

    epub [book] [output]        build a book to epub
        --log                   Minimum log level to display (Default is info; Values are debug, info, warn, error, disabled)

    mobi [book] [output]        build a book to mobi
        --log                   Minimum log level to display (Default is info; Values are debug, info, warn, error, disabled)

    serve [book]                Build then serve a gitbook from a directory
        --port                  Port for server to listen on (Default is 4000)
        --lrport                Port for livereload server to listen on (Default is 35729)
        --[no-]watch            Enable/disable file watcher (Default is true)
        --format                Format to build to (Default is website; Values are website, json, ebook)
        --log                   Minimum log level to display (Default is info; Values are debug, info, warn, error, disabled)

    install [book]              install plugins dependencies

    init [directory]            create files and folders based on contents of SUMMARY.md

[SamyPesse]

Awesome! Thanks 👍