feat(bash): add self-contained help extraction script

- Introduces a Bash script showcasing embedded help text extraction
- Implements a `show_help` function utilizing `sed` for parsing comments
- Supports `--help` and `--verbose` options for enhanced usability

snippets/bash/show_help.sh

@@ -0,0 +1,52 @@
+#!/usr/bin/env bash
+# show_help.sh – Example Bash script with embedded help section
+# SPDX-License-Identifier: MIT
+
+# Use this snippet as a pattern for Bash scripts that include their own help text
+# inside comment blocks. The `show_help` function will extract the lines between
+# `#=== HELP START ===` and `#=== HELP END ===`, strip the leading `#` and output
+# a clean help message.
+
+# ─────────────────────────────────────────────────────────────
+
+show_help() {
+  sed -n '/^#=== HELP START ===/,/^#=== HELP END ===/ {
+    /^#=== HELP START ===/d
+    /^#=== HELP END ===/d
+    s/^# *//
+    p
+  }' "$0"
+}
+
+# --- Example usage of the show_help function ---
+
+#=== HELP START ===
+# Example Script
+#
+# Usage:
+#   ./show_help.sh [options]
+#
+# Options:
+#   -h, --help    Show this help message and exit
+#   -v, --verbose Enable verbose output
+#
+# Description:
+#   This is an example of how to embed a self-contained help
+#   section in a Bash script using a simple sed-based extractor.
+#=== HELP END ===
+
+# ─────────────────────────────────────────────────────────────
+
+# Main entrypoint
+case "$1" in
+  -h|--help)
+    show_help
+    exit 0
+    ;;
+  -v|--verbose)
+    echo "Verbose mode enabled"
+    ;;
+  *)
+    echo "Run with --help for usage."
+    ;;
+esac