Consolidated the Install from Source docs (matplotlib#19155)

* Consolidated the Install from Source documentation in installing_faq.rst to INSTALL.rst

* Modified the installing_faq.rst

* Changed the filepath in installing_faq.rst

* Modified installing_faq.rst

* Add link to install from source

Co-authored-by: Tim Hoffmann <[email protected]>

Author: Utkarshp1

INSTALL.rst

@@ -93,28 +93,50 @@ If you are interested in contributing to Matplotlib development,
 running the latest source code, or just like to build everything
 yourself, it is not difficult to build Matplotlib from source.
 
+A C compiler is required.  Typically, on Linux, you will need ``gcc``, which
+should be installed using your distribution's package manager; on macOS, you
+will need xcode_; on Windows, you will need Visual Studio 2015 or later.
+
+.. _xcode: https://guide.macports.org/chunked/installing.html#installing.xcode
+
 The easiest way to get the latest development version to start contributing
 is to go to the git `repository <https://github.com/matplotlib/matplotlib>`_
 and run::
 
   git clone https://github.com/matplotlib/matplotlib.git
+  
+or::
+
+  git clone [email protected]:matplotlib/matplotlib.git
 
 If you're developing, it's better to do it in editable mode. The reason why
 is that pytest's test discovery only works for Matplotlib
 if installation is done this way. Also, editable mode allows your code changes
 to be instantly propagated to your library code without reinstalling (though
 you will have to restart your python process / kernel)::
 
+  cd matplotlib
   python -m pip install -e .
 
 If you're not developing, it can be installed from the source directory with
-a simple::
+a simple (just replace the last step)::
 
   python -m pip install .
 
 To run the tests you will need to install some additional dependencies::
 
   python -m pip install -r requirements/dev/dev-requirements.txt
+  
+Then, if you want to update your Matplotlib at any time, just do::
+
+  git pull
+
+When you run ``git pull``, if the output shows that only Python files have
+been updated, you are all set. If C files have changed, you need to run ``pip
+install -e .`` again to compile them.
+
+There is more information on :ref:`using git <using-git>` in the developer
+docs.
 
 .. warning::
 

doc/faq/installing_faq.rst

@@ -155,40 +155,4 @@ picked up by other Pythons.  If all these fail, please :ref:`let us know
 Install from source
 ===================
 
-A C compiler is required.  Typically, on Linux, you will need ``gcc``, which
-should be installed using your distribution's package manager; on macOS, you
-will need xcode_; on Windows, you will need Visual Studio 2015 or later.
-
-.. _xcode: https://guide.macports.org/chunked/installing.html#installing.xcode
-
-Clone the main source using one of::
-
-   git clone [email protected]:matplotlib/matplotlib.git
-
-or::
-
-   git clone git://github.com/matplotlib/matplotlib.git
-
-and build and install with::
-
-   cd matplotlib
-   python -mpip install .
-
-If you want to be able to follow the development branch as it changes
-just replace the last step with::
-
-   python -mpip install -e .
-
-This creates links and installs the command line script in the appropriate
-places.
-
-Then, if you want to update your Matplotlib at any time, just do::
-
-   git pull
-
-When you run ``git pull``, if the output shows that only Python files have
-been updated, you are all set. If C files have changed, you need to run ``pip
-install -e .`` again to compile them.
-
-There is more information on :ref:`using git <using-git>` in the developer
-docs.
+See :ref:`install_from_source`.