Initial commit: DCNv4 custom op mirror setup

- Add enhanced README with project structure and quick start guide
- Initialize repository with DCNv4 CUDA extension (PyTorch module)
- Include classification, detection, and segmentation subdirectories
- Reference upstream OpenGVLab DCNv4 implementation

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

segmentation/deploy/configs/mmseg/segmentation_static.py

@@ -0,0 +1,2 @@
+_base_ = ['../_base_/onnx_config.py']
+codebase_config = dict(type='mmseg', task='Segmentation', with_argmax=True)

segmentation/deploy/configs/mmseg/segmentation_tensorrt_static-512x512.py

@@ -0,0 +1,13 @@
+_base_ = ['./segmentation_static.py', '../_base_/backends/tensorrt.py']
+
+onnx_config = dict(input_shape=[512, 512])
+backend_config = dict(
+    common_config=dict(max_workspace_size=1 << 30),
+    model_inputs=[
+        dict(
+            input_shapes=dict(
+                input=dict(
+                    min_shape=[1, 3, 512, 512],
+                    opt_shape=[1, 3, 512, 512],
+                    max_shape=[1, 3, 512, 512])))
+    ])