Check that the CLI arguments passed to autosub are valid.

def validate(args):
    """
    Check that the CLI arguments passed to autosub are valid.
    """
    if args.format not in FORMATTERS:
        print(
            "Subtitle format not supported. "
            "Run with --list-formats to see all supported formats."
        )
        return False

    if args.src_language not in LANGUAGE_CODES.keys():
        print(
            "Source language not supported. "
            "Run with --list-languages to see all supported languages."
        )
        return False

    if args.dst_language not in LANGUAGE_CODES.keys():
        print(
            "Destination language not supported. "
            "Run with --list-languages to see all supported languages."
        )
        return False

    if not args.source_path:
        print("Error: You need to specify a source path.")
        return False

    return True