add readme

Signed-off-by: dchigarev <dmitry.chigarev@intel.com>

Author: dchigarev

python/lighthouse/ingress/README.md

@@ -0,0 +1,10 @@
+# Lighthouse Ingress
+
+The `lighthouse.ingress` module converts various input formats to MLIR modules.
+
+## Supported Formats
+
+#### Torch
+Convert PyTorch models to MLIR using `lighthouse.ingress.torch`.
+
+**Examples:** [torch examples](https://github.com/llvm/lighthouse/tree/main/python/examples/ingress/torch)

python/lighthouse/ingress/torch/torch_import.py

@@ -97,6 +97,7 @@ def import_from_model(
     text_module = str(module)
     if ir_context is None:
         return text_module
+    # Cross boundary from torch-mlir's mlir to environment's mlir
     return ir.Module.parse(text_module, context=ir_context)