Add package supervisor3 to the index

index/supervisor3.mk

@@ -0,0 +1,7 @@
+PACKAGES += supervisor3
+pkg_supervisor3_name = supervisor3
+pkg_supervisor3_description = OTP supervisor with additional strategies
+pkg_supervisor3_homepage = https://github.com/klarna/supervisor3
+pkg_supervisor3_fetch = git
+pkg_supervisor3_repo = https://github.com/klarna/supervisor3.git
+pkg_supervisor3_commit = master