Fixes #1420: Handle multiple definitions of standard metadata for Markdown
Fixes #1420: Handle multiple definitions of standard metadata for Markdown

ls2uper/pelican,talha131/pelican,TC01/pelican,eevee/pelican,iKevinY/pelican,goerz/pelican,catdog2/pelican,sunzhongwei/pelican,goerz/pelican,Rogdham/pelican,number5/pelican,HyperGroups/pelican,florianjacob/pelican,crmackay/pelican,koobs/pelican,simonjj/pelican,ehashman/pelican,11craft/pelican,TC01/pelican,douglaskastle/pelican,lazycoder-ru/pelican,iKevinY/pelican,levanhien8/pelican,treyhunner/pelican,deved69/pelican-1,GiovanniMoretti/pelican,ls2uper/pelican,deved69/pelican-1,51itclub/pelican,iurisilvio/pelican,UdeskDeveloper/pelican,ehashman/pelican,GiovanniMoretti/pelican,kennethlyn/pelican,karlcow/pelican,avaris/pelican,janaurka/git-debug-presentiation,treyhunner/pelican,koobs/pelican,Summonee/pelican,gymglish/pelican,GiovanniMoretti/pelican,karlcow/pelican,zackw/pelican,goerz/pelican,jvehent/pelican,simonjj/pelican,TC01/pelican,number5/pelican,jimperio/pelican,51itclub/pelican,joetboole/pelican,rbarraud/pelican,Scheirle/pelican,zackw/pelican,Polyconseil/pelican,arty-name/pelican,iurisilvio/pelican,jimperio/pelican,jvehent/pelican,ingwinlu/pelican,eevee/pelican,alexras/pelican,alexras/pelican,janaurka/git-debug-presentiation,ehashman/pelican,avaris/pelican,jo-tham/pelican,farseerfc/pelican,abrahamvarricatt/pelican,levanhien8/pelican,deanishe/pelican,btnpushnmunky/pelican,51itclub/pelican,douglaskastle/pelican,catdog2/pelican,kernc/pelican,JeremyMorgan/pelican,abrahamvarricatt/pelican,douglaskastle/pelican,JeremyMorgan/pelican,rbarraud/pelican,11craft/pelican,eevee/pelican,UdeskDeveloper/pelican,lazycoder-ru/pelican,talha131/pelican,UdeskDeveloper/pelican,treyhunner/pelican,sunzhongwei/pelican,Polyconseil/pelican,garbas/pelican,deanishe/pelican,farseerfc/pelican,florianjacob/pelican,Summonee/pelican,joetboole/pelican,Rogdham/pelican,btnpushnmunky/pelican,ingwinlu/pelican,levanhien8/pelican,ls2uper/pelican,simonjj/pelican,iurisilvio/pelican,florianjacob/pelican,catdog2/pelican,crmackay/pelican,lucasplus/pelican,kennethlyn/pelican,crmackay/pelican,deved69/pelican-1,sunzhongwei/pelican,sunzhongwei/pelican,deanishe/pelican,Summonee/pelican,jimperio/pelican,getpelican/pelican,lucasplus/pelican,HyperGroups/pelican,btnpushnmunky/pelican,karlcow/pelican,kennethlyn/pelican,gymglish/pelican,kernc/pelican,Scheirle/pelican,kernc/pelican,rbarraud/pelican,joetboole/pelican,jo-tham/pelican,lucasplus/pelican,lazycoder-ru/pelican,janaurka/git-debug-presentiation,Rogdham/pelican,HyperGroups/pelican,garbas/pelican,abrahamvarricatt/pelican,jvehent/pelican,number5/pelican,koobs/pelican,zackw/pelican,11craft/pelican,alexras/pelican,Scheirle/pelican,JeremyMorgan/pelican,garbas/pelican,gymglish/pelican,getpelican/pelican