docs: fix WaitMode and Milliseconds documentation

[husam-e]

What does this do?

• Remove line break between docs and WaitMode enum, so it shows up in pkg.go.dev documentation.
• Fixes typo in docs for Scheduler.Millisecond() and Scheduler.Milliseconds() functions.

Which issue(s) does this PR fix/relate to?

N/A

List any changes that modify/break current functionality

N/A

Have you included tests for your changes?

N/A

Did you document any new/modified functionality?

N/A

Notes

[JohnRoesler]

Thanks!