Add bash version check and help

docusaurus/docs/learn/quickstarts/network/miniziti.bash

@@ -4,6 +4,21 @@ set -o errexit
 set -o nounset
 set -o pipefail
 
+checkBashVersion() {
+    if (( "${BASH_VERSION%%.*}" < 4 )); then
+        echo "This script requires Bash major version 4 or greater." >&2
+        echo "Detected version: $BASH_VERSION" >&2
+        if [[ "$DETECTED_OS" == "macOS" ]]; then
+            echo -e "\nOn macOS, you can install bash with Homebrew:" >&2
+            echo "brew install bash" >&2
+            echo -e "\nThen run:" >&2
+            #shellcheck disable=SC2016
+            echo '"$(brew --prefix bash)" ./miniziti.bash ...' >&2
+        fi
+        exit 1;
+    fi
+}
+
 banner(){
 
     local profile="${1-}"
@@ -334,6 +349,7 @@ main(){
     DETECTED_OS="$(detectOs)"
     : "${DEBUG_MINIKUBE_TUNNEL:=0}"  # set env = 1 to trigger the minikube tunnel probe
 
+    checkBashVersion
 
     while (( $# )); do
         case "$1" in