Updated Iris install instructions

docs/iris/src/installing.rst

@@ -1,6 +1,93 @@
 .. _installing_iris:
 
 Installing Iris
-***************
+===============
 
-.. include:: ../../../INSTALL
+Iris is available using conda for the following platforms:
+
+* Linux 64-bit,
+* Mac OSX 64-bit, and
+* Windows 64-bit.
+
+.. note:: Iris currently supports and is tested against **Python 3.6** and
+          **Python 3.7**.
+
+
+.. _installing_using_conda:
+
+Installing using conda (users)
+------------------------------
+
+To install Iris using conda, you must first download and install conda,
+for example from https://docs.conda.io/en/latest/miniconda.html.
+
+Once conda is installed, you can install Iris using conda with the following
+command::
+
+  conda install -c conda-forge iris
+
+If you wish to run any of the code in the gallery you will also
+need the Iris sample data. This can also be installed using conda::
+
+  conda install -c conda-forge iris-sample-data
+
+Further documentation on using conda and the features it provides can be found
+at https://conda.io/en/latest/index.html.
+
+
+.. _installing_from_source:
+
+Installing from source (devs)
+-----------------------------
+
+The latest Iris source release is available from
+https://github.com/SciTools/iris.
+
+For instructions on how to obtain the Iris project source from GitHub see
+:ref:`forking` and :ref:`set-up-fork` for instructions.
+
+Once conda is installed, you can install Iris using conda and then activate
+it.  The example commands below assume you are in the root directory of your
+local copy of Iris::
+
+  conda env create --file=requirements/ci/iris.yml
+  conda activate iris-dev
+
+The ``requirements/ci/iris.yml`` file used to create the conda environment
+includes **all** the relevant dependencies that you need to **code**, **test**,
+and **build** the documentation.  If you wish to minimise your install you can
+remove any unwanted packages from the requirements file.
+
+.. note:: The ``requirements/ci/iris.yml`` file will always use the latest
+          tested Python version available.  For all Python versions that
+          are supported view the contents of the `requirements/ci`_ directory.
+
+.. _requirements/ci: https://github.com/tkknight/iris/tree/master/requirements/ci
+
+Finally you need to run the command to configure your shell environment
+to find your local Iris code::
+
+  python setup.py develop
+
+
+Running the tests
+-----------------
+
+To ensure your setup is configured correctly you can run the test suite using
+the command::
+
+    python setup.py test
+
+
+Custom site configuration
+-------------------------
+
+The default site configuration values can be overridden by creating the file
+``iris/etc/site.cfg``. For example, the following snippet can be used to
+specify a non-standard location for your dot executable::
+
+  [System]
+  dot_path = /usr/bin/dot
+
+An example configuration file is available in ``iris/etc/site.cfg.template``.
+See :py:func:`iris.config` for further configuration options.