[Documentation] Update Development.md

Include the platform name in the binary path as we expect to find
things relative to that.

-- https://bugs.swift.org/browse/SR-5801

Author: aciidgh

Documentation/Development.md

@@ -66,8 +66,8 @@ using a [snapshot](https://swift.org/download/#releases) from swift.org.
 	### Example:
 	```sh
 	$ cd /tmp && mkdir hello && cd hello
-	$ /path/to/swiftpm/.build/debug/swift-package init
-	$ /path/to/swiftpm/.build/debug/swift-build
+	$ /path/to/swiftpm/.build/x86_64-apple-macosx10.10/debug/swift-package init
+	$ /path/to/swiftpm/.build/x86_64-apple-macosx10.10/debug/swift-build
 	```
 
 
@@ -89,10 +89,10 @@ bootstrap script first.
 $ cd swiftpm
 
 # Rebuild just the sources.
-$ .build/debug/swift-build
+$ .build/x86_64-apple-macosx10.10/debug/swift-build
 
 # Run a single test.
-$ .build/debug/swift-test --filter BasicTests.GraphAlgorithmsTests/testCycleDetection
+$ .build/x86_64-apple-macosx10.10/debug/swift-test --filter BasicTests.GraphAlgorithmsTests/testCycleDetection
 ```
 
 Note: If you make any changes to `PackageDescription` or `PackageDescription4`