[doc] clarify getdata limit after #14897
[doc] clarify getdata limit after #14897

GETDATA is limited to blocks and transactions now and can't be used for other non-block data
instagibbs/bitcoin,jambolo/bitcoin,namecoin/namecore,sipsorcery/bitcoin,apoelstra/bitcoin,namecoin/namecore,fujicoin/fujicoin,fujicoin/fujicoin,practicalswift/bitcoin,pataquets/namecoin-core,Xekyo/bitcoin,prusnak/bitcoin,tecnovert/particl-core,rnicoll/bitcoin,namecoin/namecoin-core,namecoin/namecore,bitcoin/bitcoin,tecnovert/particl-core,EthanHeilman/bitcoin,namecoin/namecoin-core,JeremyRubin/bitcoin,yenliangl/bitcoin,bitcoinknots/bitcoin,fanquake/bitcoin,n1bor/bitcoin,dscotese/bitcoin,lateminer/bitcoin,EthanHeilman/bitcoin,qtumproject/qtum,MeshCollider/bitcoin,domob1812/bitcoin,sipsorcery/bitcoin,sstone/bitcoin,namecoin/namecoin-core,cdecker/bitcoin,bitcoinsSG/bitcoin,pataquets/namecoin-core,jamesob/bitcoin,dscotese/bitcoin,instagibbs/bitcoin,GroestlCoin/bitcoin,ElementsProject/elements,n1bor/bitcoin,pstratem/bitcoin,namecoin/namecoin-core,anditto/bitcoin,qtumproject/qtum,mruddy/bitcoin,qtumproject/qtum,Sjors/bitcoin,MeshCollider/bitcoin,rnicoll/bitcoin,pstratem/bitcoin,qtumproject/qtum,cdecker/bitcoin,ajtowns/bitcoin,kallewoof/bitcoin,andreaskern/bitcoin,fujicoin/fujicoin,bitcoinsSG/bitcoin,jlopp/statoshi,ElementsProject/elements,ElementsProject/elements,MeshCollider/bitcoin,jlopp/statoshi,Sjors/bitcoin,domob1812/namecore,ajtowns/bitcoin,AkioNak/bitcoin,sstone/bitcoin,jamesob/bitcoin,cdecker/bitcoin,domob1812/namecore,GroestlCoin/GroestlCoin,mm-s/bitcoin,ajtowns/bitcoin,practicalswift/bitcoin,bitcoinsSG/bitcoin,qtumproject/qtum,jamesob/bitcoin,yenliangl/bitcoin,MarcoFalke/bitcoin,dscotese/bitcoin,instagibbs/bitcoin,tecnovert/particl-core,MarcoFalke/bitcoin,bitcoinknots/bitcoin,sstone/bitcoin,domob1812/namecore,yenliangl/bitcoin,mruddy/bitcoin,jlopp/statoshi,GroestlCoin/GroestlCoin,jamesob/bitcoin,n1bor/bitcoin,particl/particl-core,domob1812/namecore,ajtowns/bitcoin,jambolo/bitcoin,mm-s/bitcoin,cdecker/bitcoin,jamesob/bitcoin,particl/particl-core,yenliangl/bitcoin,tecnovert/particl-core,AkioNak/bitcoin,dscotese/bitcoin,fanquake/bitcoin,anditto/bitcoin,anditto/bitcoin,fujicoin/fujicoin,pstratem/bitcoin,dscotese/bitcoin,mm-s/bitcoin,instagibbs/bitcoin,sstone/bitcoin,Xekyo/bitcoin,jnewbery/bitcoin,pstratem/bitcoin,tecnovert/particl-core,lateminer/bitcoin,domob1812/namecore,cdecker/bitcoin,andreaskern/bitcoin,bitcoin/bitcoin,domob1812/bitcoin,pstratem/bitcoin,MeshCollider/bitcoin,jambolo/bitcoin,AkioNak/bitcoin,rnicoll/bitcoin,kallewoof/bitcoin,jlopp/statoshi,EthanHeilman/bitcoin,MarcoFalke/bitcoin,tecnovert/particl-core,yenliangl/bitcoin,mm-s/bitcoin,practicalswift/bitcoin,achow101/bitcoin,namecoin/namecore,pstratem/bitcoin,GroestlCoin/GroestlCoin,bitcoinsSG/bitcoin,prusnak/bitcoin,bitcoin/bitcoin,JeremyRubin/bitcoin,particl/particl-core,andreaskern/bitcoin,apoelstra/bitcoin,Sjors/bitcoin,fujicoin/fujicoin,MarcoFalke/bitcoin,kallewoof/bitcoin,mruddy/bitcoin,sipsorcery/bitcoin,namecoin/namecore,jnewbery/bitcoin,n1bor/bitcoin,AkioNak/bitcoin,rnicoll/bitcoin,domob1812/bitcoin,fanquake/bitcoin,namecoin/namecore,lateminer/bitcoin,fanquake/bitcoin,ElementsProject/elements,anditto/bitcoin,GroestlCoin/bitcoin,jnewbery/bitcoin,jnewbery/bitcoin,apoelstra/bitcoin,ajtowns/bitcoin,dscotese/bitcoin,MarcoFalke/bitcoin,bitcoinknots/bitcoin,jambolo/bitcoin,domob1812/bitcoin,achow101/bitcoin,achow101/bitcoin,fanquake/bitcoin,andreaskern/bitcoin,GroestlCoin/GroestlCoin,mruddy/bitcoin,fanquake/bitcoin,lateminer/bitcoin,Xekyo/bitcoin,prusnak/bitcoin,namecoin/namecoin-core,practicalswift/bitcoin,n1bor/bitcoin,fujicoin/fujicoin,domob1812/bitcoin,mm-s/bitcoin,apoelstra/bitcoin,lateminer/bitcoin,andreaskern/bitcoin,domob1812/bitcoin,pataquets/namecoin-core,jamesob/bitcoin,EthanHeilman/bitcoin,pataquets/namecoin-core,bitcoin/bitcoin,sipsorcery/bitcoin,instagibbs/bitcoin,sstone/bitcoin,EthanHeilman/bitcoin,sipsorcery/bitcoin,Sjors/bitcoin,jnewbery/bitcoin,jambolo/bitcoin,instagibbs/bitcoin,pataquets/namecoin-core,bitcoin/bitcoin,achow101/bitcoin,qtumproject/qtum,mm-s/bitcoin,cdecker/bitcoin,AkioNak/bitcoin,prusnak/bitcoin,jlopp/statoshi,GroestlCoin/bitcoin,ajtowns/bitcoin,MarcoFalke/bitcoin,particl/particl-core,prusnak/bitcoin,bitcoinknots/bitcoin,rnicoll/bitcoin,apoelstra/bitcoin,achow101/bitcoin,particl/particl-core,bitcoin/bitcoin,GroestlCoin/bitcoin,bitcoinsSG/bitcoin,yenliangl/bitcoin,bitcoinsSG/bitcoin,GroestlCoin/GroestlCoin,namecoin/namecoin-core,Xekyo/bitcoin,AkioNak/bitcoin,qtumproject/qtum,andreaskern/bitcoin,JeremyRubin/bitcoin,MeshCollider/bitcoin,JeremyRubin/bitcoin,rnicoll/bitcoin,jambolo/bitcoin,n1bor/bitcoin,bitcoinknots/bitcoin,Xekyo/bitcoin,GroestlCoin/GroestlCoin,mruddy/bitcoin,achow101/bitcoin,apoelstra/bitcoin,particl/particl-core,EthanHeilman/bitcoin,practicalswift/bitcoin,domob1812/namecore,mruddy/bitcoin,sstone/bitcoin,JeremyRubin/bitcoin,JeremyRubin/bitcoin,prusnak/bitcoin,practicalswift/bitcoin,GroestlCoin/bitcoin,ElementsProject/elements,kallewoof/bitcoin,pataquets/namecoin-core,sipsorcery/bitcoin,Xekyo/bitcoin,anditto/bitcoin,ElementsProject/elements,GroestlCoin/bitcoin,kallewoof/bitcoin,MeshCollider/bitcoin,kallewoof/bitcoin,Sjors/bitcoin,lateminer/bitcoin,anditto/bitcoin,jlopp/statoshi