Extend FOIA patch spreadsheet instructions with branching
Extend FOIA patch spreadsheet instructions with branching

Add sections in 'Scripts/HowtoUpdateSpreadsheets.rst' to explain how to
use Git branches to cleanly merge upstream changes with our local
modifications to the spreadsheets.

timmvt/VistA_tt,josephsnyder/VistA,OSEHRA/VistA,OSEHRA-Sandbox/VistA,mdgeek/VistA-FHIR-CWF,shabiel/VistA,OSEHRA-Sandbox/VistA,shabiel/VistA,josephsnyder/VistA,shabiel/VistA,OSEHRA-Sandbox/VistA,apexdatasolutions/VistA,jasonli2000/VistA,mdgeek/VistA-FHIR-CWF,OSEHRA/VistA,shabiel/VistA,mdgeek/VistA-FHIR-CWF,mdgeek/VistA-FHIR-CWF,mdgeek/VistA-FHIR-CWF,apexdatasolutions/VistA,OSEHRA/VistA,jasonli2000/VistA,OSEHRA/VistA,OSEHRA/VistA,shabiel/VistA,timmvt/VistA_tt,josephsnyder/VistA,timmvt/VistA_tt,jasonli2000/VistA,josephsnyder/VistA,jasonli2000/VistA,OSEHRA-Sandbox/VistA,OSEHRA/VistA,mdgeek/VistA-FHIR-CWF,josephsnyder/VistA,timmvt/VistA_tt,shabiel/VistA,OSEHRA-Sandbox/VistA,apexdatasolutions/VistA,josephsnyder/VistA,timmvt/VistA_tt,apexdatasolutions/VistA,apexdatasolutions/VistA,OSEHRA-Sandbox/VistA