ProseMirror Test Document Builder

`prosemirror-test-builder` is a specialized utility package designed to simplify the programmatic construction of ProseMirror documents for testing purposes. It provides a comprehensive set of helper functions, often named after common HTML tags like `p`, `h1`, `ul`, and `li`, allowing developers to intuitively build nodes and marks within a default, feature-rich ProseMirror schema. The package also includes a `builders` utility for generating these helpers based on a custom schema. A key differentiating feature is its integrated tag system, which enables developers to embed named markers within document content strings (e.g., `<a>`) to precisely track and retrieve cursor positions within the generated document, significantly streamlining assertion logic in tests. This current stable version is 1.1.1, and its release cadence is generally aligned with the broader ProseMirror ecosystem, ensuring compatibility for test setups.