Fix mozilla-mobile#6362 - update new joiner build docs in README to mention requirement for Node.js to run bootstrap.sh (#6364)
Fix mozilla-mobile#6362 - update new joiner build docs in README to mention requirement for Node.js to run bootstrap.sh (#6364)


mkaply/firefox-ios,mozilla-mobile/firefox-ios,garvankeeley/firefox-ios,AaronMT/firefox-ios,Acidburn0zzz/firefox-ios,garvankeeley/firefox-ios,AaronMT/firefox-ios,st3fan/firefox-ios,mkaply/firefox-ios,garvankeeley/firefox-ios,garvankeeley/firefox-ios,flodolo/firefox-ios,mkaply/firefox-ios,mozilla-mobile/firefox-ios,Acidburn0zzz/firefox-ios,StYaphet/firefox-ios,st3fan/firefox-ios,Acidburn0zzz/firefox-ios,garvankeeley/firefox-ios,Acidburn0zzz/firefox-ios,Acidburn0zzz/firefox-ios,st3fan/firefox-ios,flodolo/firefox-ios,flodolo/firefox-ios,mkaply/firefox-ios,StYaphet/firefox-ios,st3fan/firefox-ios,flodolo/firefox-ios,mozilla-mobile/firefox-ios,st3fan/firefox-ios,Acidburn0zzz/firefox-ios,mozilla-mobile/firefox-ios,mkaply/firefox-ios,mkaply/firefox-ios,flodolo/firefox-ios,Acidburn0zzz/firefox-ios,flodolo/firefox-ios,mozilla-mobile/firefox-ios,garvankeeley/firefox-ios,AaronMT/firefox-ios,StYaphet/firefox-ios,Acidburn0zzz/firefox-ios,StYaphet/firefox-ios,flodolo/firefox-ios,AaronMT/firefox-ios,StYaphet/firefox-ios,st3fan/firefox-ios,mozilla-mobile/firefox-ios,st3fan/firefox-ios,StYaphet/firefox-ios,StYaphet/firefox-ios,AaronMT/firefox-ios,StYaphet/firefox-ios,mozilla-mobile/firefox-ios,garvankeeley/firefox-ios,mkaply/firefox-ios,st3fan/firefox-ios,AaronMT/firefox-ios,AaronMT/firefox-ios