Complete missing docstrings across OMLT codebase

[jezsadler]

ruff linting revealed the following missing docstrings:

• docs/notebooks/data/build_sin_quadratic_csv.py:1:1: D100 Missing docstring in public module
• src/omlt/block.py:33:7: D101 Missing docstring in public class
• src/omlt/block.py:34:9: D107 Missing docstring in __init__
• src/omlt/dependencies.py:1:1: D100 Missing docstring in public module
• src/omlt/formulation.py:1:1: D100 Missing docstring in public module
• src/omlt/formulation.py:82:5: D103 Missing docstring in public function
• src/omlt/gbt/gbt_formulation.py:1:1: D100 Missing docstring in public module
• src/omlt/gbt/model.py:1:1: D100 Missing docstring in public module
• src/omlt/gbt/model.py:1:7: D101 Missing docstring in public class
• src/omlt/io/init.py:1:1: D104 Missing docstring in public package
• src/omlt/io/input_bounds.py:1:1: D100 Missing docstring in public module
• src/omlt/io/keras/init.py:1:1: D104 Missing docstring in public package
• src/omlt/io/keras/keras_reader.py:1:1: D100 Missing docstring in public module
• src/omlt/io/onnx.py:1:1: D100 Missing docstring in public module
• src/omlt/io/onnx_parser.py:1:1: D100 Missing docstring in public module
• src/omlt/io/onnx_parser.py:39:9: D107 Missing docstring in __init__
• src/omlt/io/onnx_parser.py:53:9: D102 Missing docstring in public method
• src/omlt/io/torch_geometric/init.py:1:1: D104 Missing docstring in public package
• src/omlt/io/torch_geometric/build_gnn_formulation.py:1:1: D100 Missing docstring in public module
• src/omlt/io/torch_geometric/torch_geometric_reader.py:1:1: D100 Missing docstring in public module
• src/omlt/linear_tree/lt_definition.py:1:1: D100 Missing docstring in public module
• src/omlt/linear_tree/lt_formulation.py:1:1: D100 Missing docstring in public module
• src/omlt/neuralnet/activations/linear.py:1:1: D100 Missing docstring in public module
• src/omlt/neuralnet/activations/linear.py:1:5: D103 Missing docstring in public function
• src/omlt/neuralnet/activations/relu.py:1:1: D100 Missing docstring in public module
• src/omlt/neuralnet/activations/relu.py:114:9: D107 Missing docstring in __init__
• src/omlt/neuralnet/activations/relu.py:119:9: D102 Missing docstring in public method
• src/omlt/neuralnet/activations/smooth.py:1:1: D100 Missing docstring in public module
• src/omlt/neuralnet/layer.py:40:9: D107 Missing docstring in __init__
• src/omlt/neuralnet/layer.py:130:9: D105 Missing docstring in magic method
• src/omlt/neuralnet/layer.py:158:9: D107 Missing docstring in __init__
• src/omlt/neuralnet/layer.py:161:9: D105 Missing docstring in magic method
• src/omlt/neuralnet/layer.py:198:9: D107 Missing docstring in __init__
• src/omlt/neuralnet/layer.py:227:9: D105 Missing docstring in magic method
• src/omlt/neuralnet/layer.py:324:9: D107 Missing docstring in __init__
• src/omlt/neuralnet/layer.py:374:9: D105 Missing docstring in magic method
• src/omlt/neuralnet/layer.py:418:9: D107 Missing docstring in __init__
• src/omlt/neuralnet/layer.py:547:9: D107 Missing docstring in __init__
• src/omlt/neuralnet/layer.py:586:9: D105 Missing docstring in magic method
• src/omlt/neuralnet/layer.py:621:9: D107 Missing docstring in __init__
• src/omlt/neuralnet/layer.py:676:9: D105 Missing docstring in magic method
• src/omlt/neuralnet/layer.py:699:9: D107 Missing docstring in __init__
• src/omlt/neuralnet/layer.py:713:9: D102 Missing docstring in public method
• src/omlt/neuralnet/layer.py:717:9: D105 Missing docstring in magic method
• src/omlt/neuralnet/layers/full_space.py:1:1: D100 Missing docstring in public module
• src/omlt/neuralnet/layers/partition_based.py:1:1: D100 Missing docstring in public module
• src/omlt/neuralnet/layers/reduced_space.py:1:1: D100 Missing docstring in public module
• src/omlt/neuralnet/network_definition.py:1:1: D100 Missing docstring in public module
• src/omlt/neuralnet/network_definition.py:6:7: D101 Missing docstring in public class
• src/omlt/neuralnet/network_definition.py:165:9: D105 Missing docstring in magic method
• src/omlt/neuralnet/nn_formulation.py:1:1: D100 Missing docstring in public module
• src/omlt/neuralnet/nn_formulation.py:79:9: D107 Missing docstring in __init__
• src/omlt/neuralnet/nn_formulation.py:220:7: D101 Missing docstring in public class
• src/omlt/neuralnet/nn_formulation.py:244:7: D101 Missing docstring in public class
• src/omlt/neuralnet/nn_formulation.py:266:7: D101 Missing docstring in public class
• src/omlt/neuralnet/nn_formulation.py:302:9: D107 Missing docstring in __init__
• src/omlt/neuralnet/nn_formulation.py:439:9: D107 Missing docstring in __init__
• src/omlt/neuralnet/nn_formulation.py:465:9: D107 Missing docstring in __init__
• src/omlt/scaling.py:11:7: D101 Missing docstring in public class
• src/omlt/scaling.py:31:5: D103 Missing docstring in public function
• src/omlt/scaling.py:61:9: D107 Missing docstring in __init__

For each of these we should provide a docstring, unless it makes sense to change to private.

For now I've set ruff to ignore these error codes - once the docstrings are completed we should turn that checking back on again.