README: Update for new series of commands + path API

Author: JohnSundell

README.md

@@ -14,6 +14,13 @@ let output = try shellOut(to: "echo", arguments: ["Hello world"])
 print(output) // Hello world
 ```
 
+You can also easily run a series of commands at once, optionally at a given path:
+```swift
+try shellOut(to: ["mkdir NewFolder", "echo \"Hello again\" > NewFolder/File"], at: "~/CurrentFolder")
+let output = try shellOut(to: "cat File", at: "~/CurrentFolder/NewFolder")
+print(output) // Hello again
+```
+
 In case of an error, ShellOut will automatically read `STDERR` and format it nicely into a typed Swift error:
 ```swift
 do {