Add setting option to not open editor when title or msg blank

[R.G.]

RE #717

Add config option like open_editor: false which defaults to true.

This will enable a user in CI mode to not have their editor opened when leaving a title or msg blank.

[R.G.]

🎉 This PR is included in version 2.5.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

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