[#109] Add `--path` option to the `default-config` command to print default config location instead

[zixuan-x]

Resolves #109

Additional tasks

• [x] Documentation for changes provided/changed
• [ ] Tests added
• [x] Updated CHANGELOG.md

[zixuan-x]

Here are some example outputs:

• tool default-config -h

  

• tool default-config --path

  

• tool default-config

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