[docs][python] add conda-forge install instructions (#3544)

* DOC: add conda-forge install instructions

* DOC: add conda-forge instructions

* DOC: fix hyperlink

* DOC: point to installation guide

* add detailed

* Update python-package/README.rst
Co-authored-by: James Lamb <jaylamb20@gmail.com>

* Update python-package/README.rst
Co-authored-by: James Lamb <jaylamb20@gmail.com>

* rm characters

* add pip install

* add :

* Update python-package/README.rst
Co-authored-by: Nikita Titov <nekit94-08@mail.ru>

* Update python-package/README.rst
Co-authored-by: Nikita Titov <nekit94-08@mail.ru>

* remove pip from header

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

docs/Python-Intro.rst

@@ -14,7 +14,7 @@ This document gives a basic walkthrough of LightGBM Python-package.
 Install
 -------
 
-You can install LightGBM via pip
+The preferred way to install LightGBM is via pip:
 
 ::
 

python-package/README.rst

@@ -13,14 +13,13 @@ Preparation
 
 `setuptools <https://pypi.org/project/setuptools>`_ is needed.
 
-Install from `PyPI <https://pypi.org/project/lightgbm>`_ Using ``pip``
-''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
+Install from `PyPI <https://pypi.org/project/lightgbm>`_
+''''''''''''''''''''''''''''''''''''''''''''''''''''''''
 
 .. code:: sh
 
     pip install lightgbm
 
-
 You may need to install `wheel <https://pythonwheels.com>`_ via ``pip install wheel`` first.
 
 Compiled library that is included in the wheel file supports both **GPU** and **CPU** versions out of the box. This feature is experimental and available only for **Windows** currently. To use **GPU** version you only need to install OpenCL Runtime libraries. For NVIDIA and AMD GPU they are included in the ordinary drivers for your graphics card, so no action is required. If you would like your AMD or Intel CPU to act like a GPU (for testing and debugging) you can install `AMD APP SDK <https://github.com/microsoft/LightGBM/releases/download/v2.0.12/AMD-APP-SDKInstaller-v3.0.130.135-GA-windows-F-x64.exe>`_.
@@ -37,7 +36,6 @@ For **macOS** (we provide wheels for 3 newest macOS versions) users:
 
 - For version smaller than 2.1.2, **gcc-7** with **OpenMP** is required.
 
-
 Build from Sources
 ******************
 
@@ -144,6 +142,17 @@ By default, installation in environment with 32-bit Python is prohibited. Howeve
 
 It is **strongly not recommended** to use this version of LightGBM!
 
+Install from `conda-forge channel <https://anaconda.org/conda-forge/lightgbm>`_
+'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
+
+If you use ``conda`` to manage Python dependencies, you can install LightGBM using ``conda install``.
+
+**Note**: The `lightgbm conda-forge feedstock <https://github.com/conda-forge/lightgbm-feedstock>`_ is not maintained by LightGBM maintainers.
+
+.. code:: sh
+
+    conda install -c conda-forge lightgbm
+
 Install from GitHub
 '''''''''''''''''''