Remove max-width setting
Remove max-width setting

We've decided it doesn't help readability much and it makes the layout
look less tidy.

Closes #1387

annapowellsmith/openpresc,annapowellsmith/openpresc,ebmdatalab/openprescribing,annapowellsmith/openpresc,ebmdatalab/openprescribing,ebmdatalab/openprescribing,ebmdatalab/openprescribing,annapowellsmith/openpresc