Update settings.md accordingly

Author: stevapple

docs/settings.md

@@ -46,16 +46,22 @@ This controls the display of Inlay Hints. Inlay Hints are variable annotations i
 
 Trace the communication between Visual Studio Code and the SourceKit-LSP server. The output from this is sent to an Output Window called "Sourcekit Language Server"
 
+### Cross Compilation (Experimental)
+
+Cross-compilation is the act of compiling code for one computer system on a different system. The Swift compiler, which is based on LLVM, is a native cross-compiler and SwiftPM is capable of building a package for custom "destination".
+
+> **NOTE:** Cross-compilation settings are not suggested to be set globally, as different projects often target different destinations.
+
+- **Destination > SDK**
+
+The path of the SDK to compile against. The default destination SDK is determined by the environment on macOS and Windows. This adds the `--sdk` command line parameter to the relevant SwiftPM calls.
+
 ### Advanced
 
 - **Runtime Path**
 
 Where to find Swift runtime libraries. This is mainly of use when these libraries cannot be discovered via the RPATH. On Windows the runtime path is added to the `Path` environment variable. This is of less use on macOS and Linux but will be added to `DYLD_LIBRARY_PATH` and `LD_LIBRARY_PATH` environment variables respectively on each platform. This is of use when supporting non-standard SDK layouts on Windows
 
-- **SDK**
-
-The path of the target SDK to compile against. The default SDK is determined by the environment on macOS and Windows. This is of use when supporting non-standard SDK layouts on Windows and using custom SDKs. This adds the `--sdk` command line parameter to the relevant `swift` calls.
-
 - **Diagnostics**
 
 The Swift extension includes a Swift Output channel that events are logged in. You can access this by selecting menu item `View -> Output` and then selecting `Swift` in the drop down menu. Events like adding new folders, LSP server starting, errors and package resolves/updates are recorded in here. This is all useful information when trying to debug an issue with the extension. Enabling the diagnostics setting will extend this information to include considerably more information. If you want to report a bug with the extension it would be good practice to enable this setting, restart Visual Studio Code and once you have replicated your bug include the contents of the Swift Output channel in the bug report.