Accept suggestions

Co-authored-by: Pete Johanson <peter@peterjohanson.com>

.devcontainer/Dockerfile

@@ -1,8 +1,8 @@
-from zmkfirmware/zephyr-west-action-arm
+FROM zmkfirmware/zephyr-west-action-arm
 
 RUN apt-get -y update && \
     apt-get -y upgrade && \
     apt-get install --no-install-recommends -y \
     ssh \
     gpg && \
-    rm -rf /var/lib/apt/lists/*
+    rm -rf /var/lib/apt/lists/*