Double space inserts a period on Mac, confusing users

[microbit-matt-hillsdon]

This is a Mac system option but very confusing in a coding context.

Can we avoid it?

@microbit-katie's original report:

Is there a way to add an in-line comment without needing to manually delete the period that auto populates? I tried it twice thinking it would sense that I didn’t want the period and stop auto-populating it (like Word formatting), but in the end had to manually delete the period after typing out my hash.

[microbit-robert]

Previously raised here: #71

Raised on the CodeMirror repo here: codemirror/codemirror5#6401

[microbit-matt-hillsdon]

There's a slightly scary workaround suggested on the CM issue above. No real fix is possible.