feat: add terragrunt validate hook (#134)

terragrunt_validate.sh

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+
+set -e
+
+declare -a paths
+
+index=0
+
+for file_with_path in "$@"; do
+  file_with_path="${file_with_path// /__REPLACED__SPACE__}"
+
+  paths[index]=$(dirname "$file_with_path")
+
+  let "index+=1"
+done
+
+for path_uniq in $(echo "${paths[*]}" | tr ' ' '\n' | sort -u); do
+  path_uniq="${path_uniq//__REPLACED__SPACE__/ }"
+
+  pushd "$path_uniq" > /dev/null
+  terragrunt validate
+  popd > /dev/null
+done