docs(script): improve help message layout and readability

- Revamps the script's help message for better clarity and usability
- Consolidates and restructures usage, options, and arguments sections
- Simplifies help text generation using `sed` to avoid redundancy

scripts/install-git-cliff.sh

@@ -1,17 +1,27 @@
 #!/usr/bin/env bash
-# install-git-cliff.sh – fetches the latest or specified git-cliff binary
-# Usage (back-compatible):
-#   sudo ./install-git-cliff.sh                          # latest version, default arch/dir
-#   sudo ./install-git-cliff.sh 2.9.1                    # specific version
-# Extended options:
-#   sudo ./install-git-cliff.sh -a x86_64-linux-musl [<ver>]   # custom arch
-#   sudo ./install-git-cliff.sh -d /opt/tools [<ver>]          # custom install dir
-#   sudo ./install-git-cliff.sh -n [<ver>]                     # dry-run (no install)
-#   sudo ./install-git-cliff.sh -h | --help                    # help
-#
+# install-git-cliff.sh – Installs the git-cliff binary
+
+# Usage:
+#   sudo ./install-git-cliff.sh [options] [<version>]
+
+# Options:
+#   -a, --arch <triplet>   Target architecture (default: ${DEFAULT_ARCH_DISPLAY})
+#   -d, --dir  <path>      Installation directory (default: ${INSTALL_DIR_DEFAULT})
+#   -n, --dry-run          Download and verify, but do NOT install
+#   -h, --help             Show this help message
+
+# Arguments:
+#   <version>              git-cliff version to install (default: latest)
+
 # Behaviour:
-#   • If git-cliff is already in \$PATH and **no version** was requested, the script exits early.
-#   • If a specific version was requested, the installed version is compared; identical → exit, different → upgrade.
+#   • If git-cliff is already in PATH and no version was requested the script exits.
+#   • If a specific version was requested, the installed version is compared and
+#     only upgraded if it differs.
+
+# Supported architecture triplets (examples):
+#   aarch64-linux-gnu / musl / apple-darwin / pc-windows-msvc
+#   i686-linux-gnu / musl / pc-windows-msvc
+#   x86_64-linux-gnu / musl / apple-darwin / pc-windows-*
 set -euo pipefail
 
 REPO="orhun/git-cliff"
@@ -29,33 +39,7 @@ USER_VERSION_SPECIFIED=false
 # ───────────────────────────────────────────────
 
 # 0 Help function
-show_help() {
-  cat <<EOF
-install-git-cliff.sh – Installs the git-cliff binary
-
-Usage:
-  sudo ./install-git-cliff.sh [options] [<version>]
-
-Options:
-  -a, --arch <triplet>   Target architecture (default: ${DEFAULT_ARCH_DISPLAY})
-  -d, --dir  <path>      Installation directory (default: ${INSTALL_DIR_DEFAULT})
-  -n, --dry-run          Download and verify, but do NOT install
-  -h, --help             Show this help message
-
-Arguments:
-  <version>              git-cliff version to install (default: latest)
-
-Behaviour:
-  • If git-cliff is already in PATH and no version was requested the script exits.
-  • If a specific version was requested, the installed version is compared and
-    only upgraded if it differs.
-
-Supported architecture triplets (examples):
-  aarch64-linux-gnu / musl / apple-darwin / pc-windows-msvc
-  i686-linux-gnu / musl / pc-windows-msvc
-  x86_64-linux-gnu / musl / apple-darwin / pc-windows-*
-EOF
-}
+show_help() { sed -n '2,24p' "$0"; }
 
 # 1 Parse options (keeps old single-arg form)
 POSITIONAL=()