Feature/process raw

[crvernon]

This pull request adds support for loading PSS/E .RAW v33 (and compatible) case files directly into the simplenet toolbox, bringing feature parity with the MATLAB workflow for DC network reduction. Documentation, CLI, and API references are updated to reflect this new capability, and version numbers are bumped to 0.1.1a0.

New PSS/E .RAW file support:

• Added load_raw in simplenet.io.psse to parse PSS/E .RAW v33 case files, including handling of two- and three-winding transformers, switched shunts, and robust parsing of unused sections. This enables direct use of ACTIVSg synthetic grids and other PSS/E sources without conversion. [1] [2] [3] [4]
• Updated CLI and Python API to accept .RAW files as input, including detection by file extension. [1] [2]

Documentation updates:

• Expanded documentation in README.md, docs/index.md, docs/getting-started.md, and docs/cli.md to describe .RAW file support, usage examples, and details on how PSS/E data is mapped. [1] [2] [3] [4] [5]
• Added a new API reference page for simplenet.io.psse and linked it in navigation. [1] [2] [3]
• Updated the MATLAB comparison page to note that all input formats are now supported and to clarify handling of unused PSS/E sections.

Version bump:

• Bumped project, source, and citation metadata version to 0.1.1a0 to reflect the new feature. [1] [2] [3]