add hint message

Dockerfile

@@ -5,6 +5,7 @@ FROM debian:11
 COPY --from=0 /bubble/target/client /bin/bubble
 RUN <<EOF
 apt-get update && apt-get upgrade
+chmod +x /bin/bubble
 apt-get install -y curl jq neovim htop fish tmux sudo git
 useradd -m -s /bin/fish user
 echo "user ALL=(ALL) NOPASSWD: ALL" > /etc/sudoers.d/user.conf

user.fish

@@ -1,3 +1,11 @@
+if test -e /workspace/manager.sock
+    echo "Manager capability is detected. Type 'bubble' for help."
+end
+
+if test ! -e /bin/docker
+    echo "Docker is not installed. Type 'install-docker' to install if needed."
+end
+
 function install-docker
     if test -e /bin/docker
         echo "Docker is already present at /bin/docker."