Add Operator::dB

https://github.com/allsopp/p6-Operator-dB

Author: allsopp

META.list

@@ -866,3 +866,4 @@ https://raw.githubusercontent.com/0racle/p6-File-Stat/master/META6.json
 https://raw.githubusercontent.com/Kaiepi/p6-Net-Telnet/master/META6.json
 https://raw.githubusercontent.com/Kaiepi/p6-Type-EnumHOW/master/META6.json
 https://raw.githubusercontent.com/dmaestro/Seq-Bounded/master/META6.json
+https://raw.githubusercontent.com/allsopp/p6-Operator-dB/master/META6.json