Add a "spacer"/"marker" after some amount of time/criteria is met

[diego898]

What would you like to be added: I would like a "spacer" (horizontal bar, for example) to be inserted:

• after a certain amount of time without a new log,
• after a key press
• maybe regex criteria, etc.

I came across https://github.com/samwho/spacer that attempts to solve this problem - wondering if you think it should (could) be built directly into stern

Why is this needed: When coming back and forth between to view logs, its helpful to be able have some kind visual indication.

Note: k9s also lets you "mark" logs