How to use the dvc.command.base.append_doc_link function in dvc

pull_parser.add_argument(
        "-R",
        "--recursive",
        action="store_true",
        default=False,
        help="Pull cache for subdirectories of the specified directory.",
    )
    pull_parser.set_defaults(func=CmdDataPull)

    # Push
    PUSH_HELP = "Push data files to a DVC remote storage."

    push_parser = subparsers.add_parser(
        "push",
        parents=[shared_parent_parser()],
        description=append_doc_link(PUSH_HELP, "push"),
        help=PUSH_HELP,
        formatter_class=argparse.RawDescriptionHelpFormatter,
    )
    push_parser.add_argument(
        "-r", "--remote", help="Remote repository to push to."
    )
    push_parser.add_argument(
        "-a",
        "--all-branches",
        action="store_true",
        default=False,
        help="Push cache for all branches.",
    )
    push_parser.add_argument(
        "-T",
        "--all-tags",

def add_parser(subparsers, parent_parser):
    """Setup parser for `dvc init`."""
    INIT_HELP = "Initialize DVC in the current directory."
    INIT_DESCRIPTION = (
        "Initialize DVC in the current directory. Expects directory\n"
        "to be a Git repository unless --no-scm option is specified."
    )

    init_parser = subparsers.add_parser(
        "init",
        parents=[parent_parser],
        description=append_doc_link(INIT_DESCRIPTION, "init"),
        help=INIT_HELP,
        formatter_class=argparse.RawDescriptionHelpFormatter,
    )
    init_parser.add_argument(
        "--no-scm",
        action="store_true",
        default=False,
        help="Initiate dvc in directory that is "
        "not tracked by any scm tool (e.g. git).",
    )
    init_parser.add_argument(
        "-f",
        "--force",
        action="store_true",
        default=False,
        help=(

def add_parser(subparsers, parent_parser):
    GET_HELP = "Download data from DVC repository."
    get_parser = subparsers.add_parser(
        "get",
        parents=[parent_parser],
        description=append_doc_link(GET_HELP, "get"),
        help=GET_HELP,
        formatter_class=argparse.RawDescriptionHelpFormatter,
    )
    get_parser.add_argument(
        "url", help="URL of Git repository with DVC project to download from."
    )
    get_parser.add_argument("path", help="Path to data within DVC repository.")
    get_parser.add_argument(
        "-o", "--out", nargs="?", help="Destination path to put data to."
    )
    get_parser.add_argument(
        "--rev", nargs="?", help="DVC repository git revision."
    )
    get_parser.set_defaults(func=CmdGet)

def add_parser(subparsers, parent_parser):
    MOVE_HELP = "Rename or move a DVC controlled data file or a directory."
    MOVE_DESCRIPTION = (
        "Rename or move a DVC controlled data file or a directory.\n"
        "It renames and modifies the corresponding DVC-file to reflect the"
        " changes."
    )

    move_parser = subparsers.add_parser(
        "move",
        parents=[parent_parser],
        description=append_doc_link(MOVE_DESCRIPTION, "move"),
        help=MOVE_HELP,
        formatter_class=argparse.RawDescriptionHelpFormatter,
    )
    move_parser.add_argument(
        "src", help="Source path to a data file or directory."
    )
    move_parser.add_argument("dst", help="Destination path.")
    move_parser.set_defaults(func=CmdMove)

"value", nargs="?", help="(optional) Value of the option."
    )
    remote_modify_parser.add_argument(
        "-u",
        "--unset",
        default=False,
        action="store_true",
        help="Unset option.",
    )
    remote_modify_parser.set_defaults(func=CmdRemoteModify)

    REMOTE_LIST_HELP = "List available remotes."
    remote_list_parser = remote_subparsers.add_parser(
        "list",
        parents=[parent_config_parser, parent_parser],
        description=append_doc_link(REMOTE_LIST_HELP, "remote/list"),
        help=REMOTE_LIST_HELP,
        formatter_class=argparse.RawDescriptionHelpFormatter,
    )
    remote_list_parser.set_defaults(func=CmdRemoteList)

def add_parser(subparsers, parent_parser):
    TAG_HELP = "A set of commands to manage DVC tags."
    tag_parser = subparsers.add_parser(
        "tag",
        parents=[parent_parser],
        description=append_doc_link(TAG_HELP, "tag"),
        add_help=False,
    )

    tag_subparsers = tag_parser.add_subparsers(
        dest="cmd",
        help="Use DVC tag CMD --help to display command-specific help.",
    )

    fix_subparsers(tag_subparsers)

    TAG_ADD_HELP = "Add DVC tag."
    tag_add_parser = tag_subparsers.add_parser(
        "add",
        parents=[parent_parser],
        description=append_doc_link(TAG_ADD_HELP, "tag-add"),
        help=TAG_ADD_HELP,

def add_parser(subparsers, parent_parser):
    VERSION_HELP = "Show DVC version and system/environment information."

    version_parser = subparsers.add_parser(
        "version",
        parents=[parent_parser],
        description=append_doc_link(VERSION_HELP, "version"),
        help=VERSION_HELP,
        formatter_class=argparse.RawDescriptionHelpFormatter,
    )
    version_parser.set_defaults(func=CmdVersion)

def add_parser(subparsers, parent_parser):
    RUN_HELP = "Generate a stage file from a command and execute the command."
    run_parser = subparsers.add_parser(
        "run",
        parents=[parent_parser],
        description=append_doc_link(RUN_HELP, "run"),
        help=RUN_HELP,
        formatter_class=argparse.RawDescriptionHelpFormatter,
    )
    run_parser.add_argument(
        "-d",
        "--deps",
        action="append",
        default=[],
        help="Declare dependencies for reproducible cmd.",
    )
    run_parser.add_argument(
        "-o",
        "--outs",
        action="append",
        default=[],
        help="Declare output file or directory.",

cache_subparsers = cache_parser.add_subparsers(
        dest="cmd", help="Use dvc cache CMD --help for command-specific help."
    )

    fix_subparsers(cache_subparsers)

    parent_cache_config_parser = argparse.ArgumentParser(
        add_help=False, parents=[parent_config_parser]
    )
    CACHE_DIR_HELP = "Configure cache directory location."

    cache_dir_parser = cache_subparsers.add_parser(
        "dir",
        parents=[parent_parser, parent_cache_config_parser],
        description=append_doc_link(CACHE_HELP, "cache/dir"),
        help=CACHE_DIR_HELP,
        formatter_class=argparse.RawDescriptionHelpFormatter,
    )
    cache_dir_parser.add_argument(
        "-u",
        "--unset",
        default=False,
        action="store_true",
        help="Unset option.",
    )
    cache_dir_parser.add_argument(
        "value",
        help="Path to cache directory. Relative paths are resolved relative "
        "to the current directory and saved to config relative to the "
        "config file location.",
    )

def add_parser(subparsers, parent_parser):
    GC_HELP = "Collect unused data from DVC cache or a remote storage."
    GC_DESCRIPTION = (
        "Deletes all files in the cache or a remote which are not in\n"
        "use by the specified git references (defaults to just HEAD)."
    )
    gc_parser = subparsers.add_parser(
        "gc",
        parents=[parent_parser],
        description=append_doc_link(GC_DESCRIPTION, "gc"),
        help=GC_HELP,
        formatter_class=argparse.RawDescriptionHelpFormatter,
    )
    gc_parser.add_argument(
        "-a",
        "--all-branches",
        action="store_true",
        default=False,
        help="Keep data files for the tips of all git branches.",
    )
    gc_parser.add_argument(
        "-T",
        "--all-tags",
        action="store_true",
        default=False,
        help="Keep data files for all git tags.",