Tell about auto-resolving lsp-sourcekit-executable (#13)

Co-authored-by: Daniel Martín <[email protected]>

Author: DivineDominion

README.md

@@ -38,7 +38,11 @@ If you don't use `use-package`:
           "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/sourcekit-lsp")))
 ```
 
-(On macOS, you can get the path to the SourceKit-LSP executable by running `xcrun --find sourcekit-lsp` in Terminal.)
+On macOS, you can get the path to the SourceKit-LSP executable by running `xcrun --find sourcekit-lsp` in Terminal. This also works to populate the path, if your emacs shell is configured correctly: 
+
+```elisp
+(setq lsp-sourcekit-executable (string-trim (shell-command-to-string "xcrun --find sourcekit-lsp")))
+```
 
 - Finally, if you want to enable `lsp` automatically whenever you visit a `.swift` file: