Add FAQ entry for missing external dependency error

Author: kateinoigakukun

src/getting-started/troubleshooting.md

@@ -45,3 +45,11 @@ If you encounter this error, please make sure that:
 - You are using the correct target triple:
    - `--triple wasm32-unknown-wasi --static-swift-stdlib` if you installed as a *toolchain*
    - `--swift-sdk wasm32-unknown-wasi` if you installed as a *Swift SDK*
+
+## `error: missing external dependency '.../usr/lib/swift/wasi/static-executable-args.lnk'
+
+You may encounter this error while building with Swift SDK for WebAssembly and `swiftc` driver command. Unfortunately, Swift SDK does not support building with `swiftc` command yet, so you need to use `swift build` Swift Package Manager command instead.
+
+e.g. `swift build --swift-sdk <SDK name>`
+
+See also: [Compile a SwiftPM package to WebAssembly](./swift-package.md)