Default get default config which is embedded in the source file, so that this program could run without any configuration file.

DefaultCWD returns the working directory of current project, default cwd is from git rev-parse --show-toplevel command, but if the command could not execute successfully, `pwd` command will be used instead.

Load to load config from confPath with specified parser.

Save to save config with specified parser.

Parser is an interface to parse config in different ways.