dockerised_local_env: Add wget to README prerequisites

As wget is not necessarily installed already on some systems.

Change-Id: I800a5bbe79a275028f2e49628c929f0db9508d69
diff --git a/dockerised_local_env/README.md b/dockerised_local_env/README.md
index 099be72..8c2bf41 100644
--- a/dockerised_local_env/README.md
+++ b/dockerised_local_env/README.md
@@ -2,13 +2,19 @@
 
 ## Prerequisites
 
- * envsubst:
+* envsubst:
 
 ```bash
 brew install gettext
 brew link --force gettext
 ```
 
+* wget:
+
+```bash
+brew install wget
+```
+
 ## Instructions
 
 The docker compose provided in this directory is meant to orchestrate the spin up