doc: Add historical release notes for 0.18.1
doc: Add historical release notes for 0.18.1

anditto/bitcoin,n1bor/bitcoin,nikkitan/bitcoin,practicalswift/bitcoin,wellenreiter01/Feathercoin,yenliangl/bitcoin,domob1812/bitcoin,MeshCollider/bitcoin,pataquets/namecoin-core,domob1812/namecore,sipsorcery/bitcoin,jtimon/bitcoin,jlopp/statoshi,jlopp/statoshi,jamesob/bitcoin,mruddy/bitcoin,achow101/bitcoin,Xekyo/bitcoin,ahmedbodi/vertcoin,JeremyRubin/bitcoin,ElementsProject/elements,particl/particl-core,litecoin-project/litecoin,namecoin/namecore,mm-s/bitcoin,domob1812/bitcoin,GroestlCoin/bitcoin,jlopp/statoshi,jonasschnelli/bitcoin,bitcoinknots/bitcoin,CryptArc/bitcoin,andreaskern/bitcoin,JeremyRubin/bitcoin,mitchellcash/bitcoin,ahmedbodi/vertcoin,jonasschnelli/bitcoin,andreaskern/bitcoin,domob1812/bitcoin,instagibbs/bitcoin,bitcoinknots/bitcoin,bitcoinsSG/bitcoin,Xekyo/bitcoin,tecnovert/particl-core,gjhiggins/vcoincore,fanquake/bitcoin,andreaskern/bitcoin,rnicoll/bitcoin,bitcoinsSG/bitcoin,rnicoll/dogecoin,fanquake/bitcoin,CryptArc/bitcoin,midnightmagic/bitcoin,qtumproject/qtum,prusnak/bitcoin,mruddy/bitcoin,wellenreiter01/Feathercoin,GroestlCoin/GroestlCoin,rnicoll/bitcoin,ajtowns/bitcoin,bitcoin/bitcoin,vertcoin/vertcoin,pstratem/bitcoin,apoelstra/bitcoin,qtumproject/qtum,peercoin/peercoin,mm-s/bitcoin,dscotese/bitcoin,tjps/bitcoin,rnicoll/bitcoin,fujicoin/fujicoin,alecalve/bitcoin,mm-s/bitcoin,bitcoinsSG/bitcoin,bitcoinknots/bitcoin,namecoin/namecoin-core,wellenreiter01/Feathercoin,GroestlCoin/bitcoin,pataquets/namecoin-core,alecalve/bitcoin,n1bor/bitcoin,sstone/bitcoin,mm-s/bitcoin,mruddy/bitcoin,domob1812/namecore,GroestlCoin/bitcoin,fujicoin/fujicoin,instagibbs/bitcoin,vertcoin/vertcoin,namecoin/namecoin-core,JeremyRubin/bitcoin,ajtowns/bitcoin,bitcoinknots/bitcoin,practicalswift/bitcoin,ajtowns/bitcoin,mm-s/bitcoin,instagibbs/bitcoin,AkioNak/bitcoin,jamesob/bitcoin,kallewoof/bitcoin,FeatherCoin/Feathercoin,bitcoin/bitcoin,achow101/bitcoin,jonasschnelli/bitcoin,sstone/bitcoin,namecoin/namecoin-core,practicalswift/bitcoin,fanquake/bitcoin,pataquets/namecoin-core,MeshCollider/bitcoin,MarcoFalke/bitcoin,sstone/bitcoin,MarcoFalke/bitcoin,vertcoin/vertcoin,domob1812/bitcoin,rnicoll/dogecoin,monacoinproject/monacoin,GroestlCoin/GroestlCoin,fujicoin/fujicoin,dscotese/bitcoin,kallewoof/bitcoin,jtimon/bitcoin,alecalve/bitcoin,anditto/bitcoin,JeremyRubin/bitcoin,jambolo/bitcoin,domob1812/bitcoin,fujicoin/fujicoin,MarcoFalke/bitcoin,qtumproject/qtum,achow101/bitcoin,kallewoof/bitcoin,ahmedbodi/vertcoin,jlopp/statoshi,ahmedbodi/vertcoin,jnewbery/bitcoin,mm-s/bitcoin,tjps/bitcoin,sipsorcery/bitcoin,monacoinproject/monacoin,Xekyo/bitcoin,anditto/bitcoin,cdecker/bitcoin,MeshCollider/bitcoin,namecoin/namecore,kallewoof/bitcoin,bitcoin/bitcoin,achow101/bitcoin,jambolo/bitcoin,AkioNak/bitcoin,EthanHeilman/bitcoin,GroestlCoin/GroestlCoin,pataquets/namecoin-core,jamesob/bitcoin,gjhiggins/vcoincore,tjps/bitcoin,jambolo/bitcoin,sipsorcery/bitcoin,cdecker/bitcoin,fanquake/bitcoin,alecalve/bitcoin,lateminer/bitcoin,peercoin/peercoin,mitchellcash/bitcoin,cdecker/bitcoin,jambolo/bitcoin,ElementsProject/elements,cdecker/bitcoin,gjhiggins/vcoincore,pstratem/bitcoin,tecnovert/particl-core,monacoinproject/monacoin,MeshCollider/bitcoin,DigitalPandacoin/pandacoin,monacoinproject/monacoin,mitchellcash/bitcoin,monacoinproject/monacoin,gjhiggins/vcoincore,FeatherCoin/Feathercoin,tecnovert/particl-core,jnewbery/bitcoin,bitcoin/bitcoin,instagibbs/bitcoin,peercoin/peercoin,ajtowns/bitcoin,vertcoin/vertcoin,DigitalPandacoin/pandacoin,lateminer/bitcoin,peercoin/peercoin,DigitalPandacoin/pandacoin,sstone/bitcoin,jtimon/bitcoin,bitcoinsSG/bitcoin,Xekyo/bitcoin,yenliangl/bitcoin,mitchellcash/bitcoin,peercoin/peercoin,n1bor/bitcoin,FeatherCoin/Feathercoin,AkioNak/bitcoin,mruddy/bitcoin,anditto/bitcoin,namecoin/namecore,GroestlCoin/GroestlCoin,litecoin-project/litecoin,yenliangl/bitcoin,namecoin/namecoin-core,ElementsProject/elements,Sjors/bitcoin,DigitalPandacoin/pandacoin,jtimon/bitcoin,pataquets/namecoin-core,MarcoFalke/bitcoin,FeatherCoin/Feathercoin,lateminer/bitcoin,domob1812/namecore,MarcoFalke/bitcoin,ElementsProject/elements,particl/particl-core,fujicoin/fujicoin,wellenreiter01/Feathercoin,DigitalPandacoin/pandacoin,rnicoll/dogecoin,bitcoin/bitcoin,sipsorcery/bitcoin,FeatherCoin/Feathercoin,EthanHeilman/bitcoin,CryptArc/bitcoin,instagibbs/bitcoin,rnicoll/bitcoin,GroestlCoin/bitcoin,dscotese/bitcoin,dscotese/bitcoin,andreaskern/bitcoin,jnewbery/bitcoin,jtimon/bitcoin,prusnak/bitcoin,tjps/bitcoin,sipsorcery/bitcoin,fujicoin/fujicoin,Sjors/bitcoin,n1bor/bitcoin,cdecker/bitcoin,sstone/bitcoin,n1bor/bitcoin,dscotese/bitcoin,MarcoFalke/bitcoin,apoelstra/bitcoin,tjps/bitcoin,pstratem/bitcoin,tecnovert/particl-core,cdecker/bitcoin,gjhiggins/vcoincore,litecoin-project/litecoin,apoelstra/bitcoin,jambolo/bitcoin,yenliangl/bitcoin,mitchellcash/bitcoin,pstratem/bitcoin,jonasschnelli/bitcoin,tecnovert/particl-core,midnightmagic/bitcoin,rnicoll/bitcoin,AkioNak/bitcoin,kallewoof/bitcoin,ahmedbodi/vertcoin,apoelstra/bitcoin,AkioNak/bitcoin,rnicoll/bitcoin,achow101/bitcoin,jnewbery/bitcoin,particl/particl-core,jamesob/bitcoin,ahmedbodi/vertcoin,lateminer/bitcoin,qtumproject/qtum,GroestlCoin/bitcoin,vertcoin/vertcoin,sstone/bitcoin,particl/particl-core,alecalve/bitcoin,AkioNak/bitcoin,qtumproject/qtum,namecoin/namecoin-core,GroestlCoin/GroestlCoin,Xekyo/bitcoin,yenliangl/bitcoin,mruddy/bitcoin,pstratem/bitcoin,apoelstra/bitcoin,domob1812/namecore,alecalve/bitcoin,midnightmagic/bitcoin,practicalswift/bitcoin,particl/particl-core,pataquets/namecoin-core,CryptArc/bitcoin,Xekyo/bitcoin,namecoin/namecore,jnewbery/bitcoin,nikkitan/bitcoin,EthanHeilman/bitcoin,andreaskern/bitcoin,dscotese/bitcoin,lateminer/bitcoin,prusnak/bitcoin,instagibbs/bitcoin,JeremyRubin/bitcoin,litecoin-project/litecoin,MeshCollider/bitcoin,Sjors/bitcoin,achow101/bitcoin,CryptArc/bitcoin,JeremyRubin/bitcoin,jlopp/statoshi,practicalswift/bitcoin,rnicoll/dogecoin,MeshCollider/bitcoin,midnightmagic/bitcoin,GroestlCoin/GroestlCoin,anditto/bitcoin,tjps/bitcoin,domob1812/namecore,EthanHeilman/bitcoin,wellenreiter01/Feathercoin,domob1812/bitcoin,wellenreiter01/Feathercoin,fanquake/bitcoin,midnightmagic/bitcoin,jamesob/bitcoin,EthanHeilman/bitcoin,practicalswift/bitcoin,prusnak/bitcoin,DigitalPandacoin/pandacoin,qtumproject/qtum,nikkitan/bitcoin,qtumproject/qtum,namecoin/namecoin-core,jambolo/bitcoin,tecnovert/particl-core,jtimon/bitcoin,andreaskern/bitcoin,bitcoin/bitcoin,nikkitan/bitcoin,bitcoinknots/bitcoin,mitchellcash/bitcoin,FeatherCoin/Feathercoin,particl/particl-core,bitcoinsSG/bitcoin,ajtowns/bitcoin,anditto/bitcoin,litecoin-project/litecoin,peercoin/peercoin,vertcoin/vertcoin,yenliangl/bitcoin,ajtowns/bitcoin,rnicoll/dogecoin,Sjors/bitcoin,sipsorcery/bitcoin,namecoin/namecore,prusnak/bitcoin,pstratem/bitcoin,fanquake/bitcoin,n1bor/bitcoin,jamesob/bitcoin,apoelstra/bitcoin,monacoinproject/monacoin,mruddy/bitcoin,litecoin-project/litecoin,nikkitan/bitcoin,namecoin/namecore,ElementsProject/elements,ElementsProject/elements,bitcoinsSG/bitcoin,midnightmagic/bitcoin,jlopp/statoshi,gjhiggins/vcoincore,Sjors/bitcoin,jonasschnelli/bitcoin,GroestlCoin/bitcoin,EthanHeilman/bitcoin,CryptArc/bitcoin,prusnak/bitcoin,kallewoof/bitcoin,lateminer/bitcoin,nikkitan/bitcoin,domob1812/namecore