added directions to use run command.

README.md

@@ -234,6 +234,33 @@ zvm clean
 
 Use `clean` to remove build artifacts (Good if you're on Windows).
 
+## Run installed version of Zig without switching your default
+
+If you want to run a version of Zig without setting it as your default, the new `run` command is your friend.
+
+```sh
+zig version
+# 0.13.0
+
+zvm run 0.11.0 version
+# 0.11.0
+
+zig version
+# 0.13.0
+```
+This can be helpful if you want to test your project on a newer version of Zig without having to switch between bins, or on alternative flavor of Zig.
+
+## How to use with alternative VMUs
+Make sure you switch your VMU before using `run`.
+
+```sh
+zvm vmu zig mach
+run mach-latest version
+# 0.14.0-dev.1911+3bf89f55c
+```
+
+If you would like to run the currently set Zig, please keep using the standard `zig` command.
+
 ## Set Version Map Source
 
 ZVM lets choose your vendor for Zig and ZLS. This is great if your company hosts it's own internal fork of Zig, you prefer a different flavor of the language, like Mach.