Stubs docs with "micro:bit" in them get extra space (a <br>) in autocomplete etc

[microbit-matt-hillsdon]

Bug Description

Look at the autocomplete docs for power.deep_sleep or NeoPixel.write or the many others that contain micro:bit in the first line.
There's some unexplained space. Removing the colon in the docs fixes it.
Presumably an error of some kind in the docstring -> reST -> Markdown -> HTML chain of doom.

Expected behavior

Space as per all other equivalent docs.

Screenshots