## Summary - Add feature to specify a custom typeshed from within Markdown-based tests - Port "builtins" unit tests from `infer.rs` to Markdown tests, part of #13696 ## Test Plan - Tests for the custom typeshed feature - New Markdown tests for deleted Rust unit tests
Markdown files within the mdtest/ subdirectory are tests of type inference and type checking;
executed by the tests/mdtest.rs integration test.
See crates/red_knot_test/README.md for documentation of this test format.