Add file location to docs of ts_web_test.static_files

Closes #318

PiperOrigin-RevId: 221325666
diff --git a/internal/karma/ts_web_test.bzl b/internal/karma/ts_web_test.bzl
index 728b887..261bfb2 100644
--- a/internal/karma/ts_web_test.bzl
+++ b/internal/karma/ts_web_test.bzl
@@ -185,7 +185,9 @@
             doc = "Runtime dependencies",
         ),
         "static_files": attr.label_list(
-            doc = """Arbitrary files which to be served.""",
+            doc = """Arbitrary files which to be served. Files are served at:
+            `/base/<WORKSPACE_NAME>/<path-to-file>`, e.g. 
+            `/base/build_bazel_rules_typescript/examples/testing/static_script.js`""",
             allow_files = True,
         ),
         "karma": attr.label(