Atma.js IO Middleware Base

This package, `atma-io-middleware-base` (current stable version 1.0.51), serves as a foundational utility for abstracting and creating custom middleware extensions for the `atma-io` library. It simplifies the process of integrating custom file processing logic—such as reading, compiling, or preprocessing files—into the `atma-io` ecosystem. Developers use it to define synchronous `process` or asynchronous `processAsync` methods that transform file content, returning an object with the modified content and an optional source map. Its configuration can be extended via `package.json` under the specific middleware's name. As part of the Atma.js Project, this package's development appears to be inactive, with the last known activity dating back to 2017, suggesting an abandoned or unmaintained status.