updated installation instructions

Author: RemDelaporteMathurin

docs/source/installation.rst

@@ -3,13 +3,13 @@ Installation
 ============
 
 FESTIM is installed in two steps:
-    1. `Installing FEniCS`_ through Anaconda or Docker
-    2. `Installing FESTIM`_ through pip on the FEniCS environment
+    1. `Installing FEniCSx`_ through Anaconda or Docker
+    2. `Installing FESTIM`_ through pip in the FEniCS environment
 
-Installing FEniCS
+Installing FEniCSx
 -----------------
 
-FEniCS can be installed with Anaconda on MacOs and Linux. 
+FEniCSx can be installed with Anaconda on MacOs and Linux. 
 In order to use the Anaconda distribution on Windows, 
 use the `Windows Subsystem for Linux <https://learn.microsoft.com/en-us/windows/wsl/install>`_. 
 
@@ -38,56 +38,13 @@ then run the following commands::
 
     conda create -n festim-env
     conda activate festim-env       
-    conda install -c conda-forge fenics numpy=1.24
-
-Alternatively, It can be installed using `Docker <https://www.docker.com/>`_::
-
-    docker run -ti -v $(pwd):/home/fenics/shared quay.io/fenicsproject/stable:latest
-
-.. note::
-    :code:`$(pwd)` needs to be replaced by :code:`${PWD}` on Windows
-
-
-For more information on how to install FEniCS, see `Download <https://fenicsproject.org/download/archive/>`_ on the FEniCS website.
+    conda install -c conda-forge fenics-dolfinx tqdm
 
 
 Installing FESTIM
 -----------------
 
-FESTIM can then be installed using pip::
-
-    pip install FESTIM
-
-Specific versions of FESTIM can be installed with::
-
-    pip install FESTIM==[version]
-
-with the desired version tag.  For example::
-
-    pip install FESTIM==0.9
-
-To upgrade FESTIM to the latest version, run::
-
-    pip install --upgrade FESTIM
-
-To uninstall FESTIM, run::
-
-    pip uninstall FESTIM
-
-
-Installing the ``fenicsx`` branch version
--------------------------------------------
-
 This version of FESTIM is under development and is not yet available on PyPI.
-It runs on ``dolfinx`` instead of ``fenics`` and can be installed on Linux and MacOS.
-If you are on Windows, you can use the Windows Subsystem for Linux (simply follow the instructions above).
-
-Create a conda environment with ``dolfinx``::
-
-    conda create -n festim-env
-    conda activate festim-env       
-    conda install -c conda-forge fenics-dolfinx tqdm
-
-Install the correct FESTIM version with::
+FESTIM can then be installed using pip::
 
     pip install git+https://github.com/FESTIM-dev/FESTIM@fenicsx