Better documentation for Contributing (#2781)

* Create CONTRIBUTING.md

* Update README.md

* Update CONTRIBUTING.md

* Update README.md

* Update CONTRIBUTING.md

Co-Authored-By: Nikita Titov <nekit94-08@mail.ru>

* Update Development-Guide.rst

* Update README.md

Co-Authored-By: James Lamb <jaylamb20@gmail.com>

Co-authored-by: Nikita Titov <nekit94-08@mail.ru>
Co-authored-by: James Lamb <jaylamb20@gmail.com>

CONTRIBUTING.md

@@ -0,0 +1,8 @@
+LightGBM has been developed and used by many active community members. Your help is very valuable to make it better for everyone.
+
+- Check for the [Roadmap](https://github.com/microsoft/LightGBM/projects/1) and the [Feature Requests Hub](https://github.com/microsoft/LightGBM/issues/2302), and submit pull requests to address chosen issue. If you need development guideline, you can check the [Development Guide](https://github.com/microsoft/LightGBM/blob/master/docs/Development-Guide.rst) or directly ask us in Issues/Pull Requests.
+- Contribute to the [tests](https://github.com/microsoft/LightGBM/tree/master/tests) to make it more reliable.
+- Contribute to the [documentation](https://github.com/microsoft/LightGBM/tree/master/docs) to make it clearer for everyone.
+- Contribute to the [examples](https://github.com/microsoft/LightGBM/tree/master/examples) to share your experience with other users.
+- Add your stories and experience to [Awesome LightGBM](https://github.com/microsoft/LightGBM/blob/master/examples/README.md). If LightGBM helped you in a machine learning competition or some research application, we want to hear about it!
+- [Open an issue](https://github.com/microsoft/LightGBM/issues) to report problems or recommend new features.

README.md

@@ -94,14 +94,8 @@ Support
 How to Contribute
 -----------------
 
-LightGBM has been developed and used by many active community members. Your help is very valuable to make it better for everyone.
+Check [CONTRIBUTING](https://github.com/microsoft/LightGBM/blob/master/CONTRIBUTING.md) page.
 
-- Contribute to the [tests](https://github.com/microsoft/LightGBM/tree/master/tests) to make it more reliable.
-- Contribute to the [documentation](https://github.com/microsoft/LightGBM/tree/master/docs) to make it clearer for everyone.
-- Contribute to the [examples](https://github.com/microsoft/LightGBM/tree/master/examples) to share your experience with other users.
-- Look for [issues with tag "help wanted"](https://github.com/microsoft/LightGBM/issues?q=is%3Aissue+is%3Aopen+label%3A%22help+wanted%22) and submit pull requests to address them.
-- Add your stories and experience to [Awesome LightGBM](https://github.com/microsoft/LightGBM/blob/master/examples/README.md). If LightGBM helped you in a machine learning competition or some research application, we want to hear about it!
-- [Open an issue](https://github.com/microsoft/LightGBM/issues) to report problems or recommend new features.
 
 Microsoft Open Source Code of Conduct
 -------------------------------------

docs/Development-Guide.rst

@@ -27,7 +27,7 @@ Important Classes
 +-------------------------+----------------------------------------------------------------------------------------+
 | ``DatasetLoader``       | Used to construct dataset                                                              |
 +-------------------------+----------------------------------------------------------------------------------------+
-| ``Feature``             | Stores one column feature                                                              |
+| ``FeatureGroup``        | Stores the data of feature, could be multiple features                                 |
 +-------------------------+----------------------------------------------------------------------------------------+
 | ``Metric``              | Evaluation metrics                                                                     |
 +-------------------------+----------------------------------------------------------------------------------------+