Add ballpark timings

Author: mnvr

az/17-swift-heap/Package.swift

@@ -8,8 +8,6 @@ let package = Package(
       .package(url: "https://github.com/apple/swift-collections", branch: "release/1.1"),
     ],
     targets: [
-        // Targets are the basic building blocks of a package, defining a module or a test suite.
-        // Targets can depend on other targets in this package and products from dependencies.
         .executableTarget(
             name: "17",
             dependencies: [

az/17-swift-heap/README.md

@@ -17,3 +17,6 @@ with the full input (must be present in your checkout!), and also prints the
 time it took:
 
     make time
+
+This version with the proper heap is indeed around 4x faster than 17.swift. On
+my machine, this takes around 0.13 s on the full input, while that takes 0.5 s.