Allow to keep line break after full stop

[lorenzwalthert]

trafficstars

The method of starting each sentence on a new line and abiding by 80 character line width rule has the advantage:

• to abide by 80 character line width.
• edits in one sentence cannot affect the diff of other sentences.

[lorenzwalthert]

Reference: https://github.com/lorenzwalthert/styler/pull/14