add warning re: using env vars to rails example
add warning re: using env vars to rails example

hardikjain29/docs,bogdanboss/docs,taz77/docs,hardikjain29/docs,Aonepathan/docs,L2G/docs,L2G/docs,hardikjain29/docs,ksigler7/docs,GilUpstream/docs,Whatthefoxsays/docs,Aonepathan/docs,L2G/docs,katieporter/docs,ksigler7/docs,katieporter/docs,hardikjain29/docs,Whatthefoxsays/docs,katieporter/docs,Ranhiru/docs,Ranhiru/docs,Ranhiru/docs,GilUpstream/docs,jacobmovingfwd/docs,sendgrid/docs,taz77/docs,bogdanboss/docs,sendgrid/docs,Zaftula/docs,jacobmovingfwd/docs,katieporter/docs,jacobmovingfwd/docs,Aonepathan/docs,taz77/docs,Zaftula/docs,sendgrid/docs,Ranhiru/docs,L2G/docs,GilUpstream/docs,Aonepathan/docs,Zaftula/docs,Zaftula/docs,Aonepathan/docs,awwa/docs,awwa/docs,Ranhiru/docs,bogdanboss/docs,awwa/docs,jacobmovingfwd/docs,Whatthefoxsays/docs,katieporter/docs,Zaftula/docs,bogdanboss/docs,bogdanboss/docs,L2G/docs,awwa/docs,taz77/docs,awwa/docs,taz77/docs,GilUpstream/docs,ksigler7/docs,hardikjain29/docs,jacobmovingfwd/docs,GilUpstream/docs