feat(clew): extract Ren'Py ASTs

src/clew/BUILD.bazel

@@ -1,8 +1,16 @@
-load("@rules_python//python:defs.bzl", "py_binary")
+load("@rules_python//python:defs.bzl", "py_binary", "py_library")
 
 py_binary(
     name = "clew",
     srcs = ["clew.py"],
     main = "clew.py",
-    deps = ["//third_party/python:rpycdec"],
+    deps = [
+        ":extract_renpy_ast",
+        "//third_party/python:rpycdec",
+    ],
+)
+
+py_library(
+    name = "extract_renpy_ast",
+    srcs = ["extract_renpy_ast.py"],
 )