chore(snippets): add bash script template

snippets/script.template.bash

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+
+set -euo 'pipefail'
+
+ERROR_GENERIC=1
+ERROR_REQUIRED_TOOL_MISSING=2
+
+pre_flight() {
+    REQUIRED_TOOLS=(
+        'xargs'
+		'…'
+    )
+    for TOOL in ${REQUIRED_TOOLS[@]}
+    do
+        if ! ( which "$TOOL" > '/dev/null' )
+        then
+            echo -e "missing required tool: $TOOL" >&2
+            exit $ERROR_REQUIRED_TOOL_MISSING
+        fi
+    done
+}
+
+pre_flight
+# …