add rules_shell

Author: benjaminp

MODULE.bazel

@@ -5,4 +5,5 @@ module(
 
 bazel_dep(name = "googletest", version = "1.16.0")
 bazel_dep(name = "rules_python", version = "1.2.0")
-bazel_dep(name = "rules_cc", version = "0.2.14")
+bazel_dep(name = "rules_cc", version = "0.2.16")
+bazel_dep(name = "rules_shell", version = "0.6.1")