Update FAQ text on dormant practices
Update FAQ text on dormant practices

As suggested in:
https://github.com/ebmdatalab/openprescribing/issues/891#issuecomment-401822266

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