add: stix2 pattern validator requirements
add: stix2 pattern validator requirements

VirusTotal/misp-modules,MISP/misp-modules,VirusTotal/misp-modules,MISP/misp-modules,VirusTotal/misp-modules,amuehlem/misp-modules,amuehlem/misp-modules,MISP/misp-modules,amuehlem/misp-modules