Update contributing doc to include links to the developer guides (NVI…

…DIA#11390)

Adds links to the developer guides to the contributing.md

Closes NVIDIA#11348

Authors:
  - David Wendt (https://github.com/davidwendt)

Approvers:
  - Mark Harris (https://github.com/harrism)
  - Vyas Ramasubramani (https://github.com/vyasr)

URL: rapidsai/cudf#11390

CONTRIBUTING.md

@@ -380,6 +380,13 @@ Now code linters and formatters will be run each time you commit changes.
 
 You can skip these checks with `git commit --no-verify` or with the short version `git commit -n`.
 
+## Developer Guidelines
+
+The [C++ Developer Guide](cpp/docs/DEVELOPER_GUIDE.md) includes details on contributing to libcudf C++ code.
+
+The [Python Developer Guide](https://docs.rapids.ai/api/cudf/stable/developer_guide/index.html) includes details on contributing to cuDF Python code.
+
+
 ## Attribution
 
 Portions adopted from https://github.com/pytorch/pytorch/blob/master/CONTRIBUTING.md

docs/cudf/README.md

@@ -3,4 +3,4 @@
 This directory contains the documentation of cuDF Python.
 For more information on how to write, build, and read the documentation,
 see 
-[the developer documentation](https://github.com/rapidsai/cudf/blob/main/docs/cudf/source/developer_guide/documentation.md).
+[the developer documentation](https://github.com/rapidsai/cudf/blob/HEAD/docs/cudf/source/developer_guide/documentation.md).