Add missing Chef 13.8 release to the notes
Add missing Chef 13.8 release to the notes

Signed-off-by: Tim Smith <764ef62106582a09ed09dfa0b6bff7c05fd7d1e4@chef.io>

tomdoherty/chef,martinisoft/chef,mattray/chef,Ppjet6/chef,higanworks/chef,mwrock/chef,chef/chef,juliandunn/chef,tomdoherty/chef,jaymzh/chef,nvwls/chef,higanworks/chef,Ppjet6/chef,jaymzh/chef,juliandunn/chef,juliandunn/chef,mwrock/chef,gene1wood/chef,MsysTechnologiesllc/chef,Ppjet6/chef,tomdoherty/chef,nvwls/chef,chef/chef,higanworks/chef,higanworks/chef,mattray/chef,tas50/chef-1,gene1wood/chef,jaymzh/chef,mattray/chef,Tensibai/chef,martinisoft/chef,tas50/chef-1,martinisoft/chef,mattray/chef,Tensibai/chef,gene1wood/chef,nvwls/chef,tas50/chef-1,gene1wood/chef,nvwls/chef,nvwls/chef,Ppjet6/chef,MsysTechnologiesllc/chef,chef/chef,mattray/chef,Ppjet6/chef,Tensibai/chef,tomdoherty/chef,MsysTechnologiesllc/chef,tas50/chef-1,juliandunn/chef,Tensibai/chef,martinisoft/chef,chef/chef,nvwls/chef,Ppjet6/chef,higanworks/chef,tomdoherty/chef,mwrock/chef,MsysTechnologiesllc/chef,Tensibai/chef,martinisoft/chef,mwrock/chef,jaymzh/chef,juliandunn/chef