docs: updates Homebrew tap repo.

Author: outofcoffee

docs/run_imposter_cli.md

@@ -40,9 +40,21 @@ You must have [Docker](https://docs.docker.com/get-docker/) or a JVM installed.
 
 If you have Homebrew installed:
 
-    brew tap gatehill/imposter
+    brew tap imposter-project/imposter
     brew install imposter
 
+<details markdown>
+<summary>Homebrew installation troubleshooting</summary>
+
+If you previously installed Imposter using Homebrew from the deprecated tap `gatehill/imposter`, you may need to run the following command to update your Homebrew installation:
+
+```shell
+brew untap gatehill/imposter
+brew tap imposter-project/imposter
+```
+
+</details>
+
 ### Shell script
 
 Or, use this one liner (macOS and Linux only):