doc: include pip in README

Author: james-d-mitchell

README.md

@@ -34,9 +34,14 @@ some related projects are [here](https://github.com/libsemigroups).
 
 # Installation
 
-It is currently only possible to install `libsemigroups_pybind11` using
-conda or from its sources. We plan to add the option of installing with
-`pip` in the future.
+## Installing with pip
+
+It's possible to install `libsemigroups_pybind11` using `pip` via one of:
+
+    pip install libsemigroups_pybind11
+    pip3 install libsemigroups_pybind11
+    python -m pip install libsemigroups_pybind11
+    python3 -m pip install libsemigroups_pybind11
 
 ## Installing with conda
 
@@ -76,7 +81,7 @@ Assuming that you have `libsemigroups` installed you can install
 To build `libsemigroups_pybind11` from a release archive:
 
     curl -L -O https://github.com/libsemigroups/libsemigroups_pybind11/releases/latest/download/libsemigroups_pybind11-0.2.0.tar.gz
-    tar -xf libsemigroups_pybind11-0.2.0.tar.gz 
+    tar -xf libsemigroups_pybind11-0.2.0.tar.gz
     rm -f libsemigroups_pybind11-0.2.0.tar.gz
     cd libsemigroups_pybind11-0.2.0
     pip install .
@@ -92,7 +97,7 @@ The following are required to be able to build the documentation:
 Assuming you already have `python3` install, on Mac OSX you can install
 all of the above by doing:
 
-    python3 -m pip3 install -r docs/requirements 
+    python3 -m pip3 install -r docs/requirements
 
 Then it ought to be possible to just run `make doc` in the
 `libsemigroups` directory.

docs/source/index.rst

@@ -8,7 +8,7 @@ What is ``libsemigroups``?
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 ``libsemigroups``  is a C++14 library containing implementations of several
-algorithms for computing finite and finitely presented semigroups. 
+algorithms for computing finite and finitely presented semigroups.
 Namely:
 
 - the `Froidure-Pin algorithm`_ for computing finite semigroups
@@ -20,20 +20,20 @@ Namely:
   semigroups which act on sets.
 
 ``libsemigroups_pybind11`` is a python package exposing much (but not all) of
-the functionality of ``libsemigroups``. 
+the functionality of ``libsemigroups``.
 
 The development version of ``libsemigroups_pybind11`` is available on github_,
 and some related projects are here_.
 
 .. _github: https://github.com/libsemigroups/libsemigroups_pybind11
-.. _here: https://github.com/libsemigroups 
+.. _here: https://github.com/libsemigroups
 
 .. _Froidure-Pin algorithm: https://www.irif.fr/~jep/PDF/Rio.pdf
 .. _Todd-Coxeter algorithm: https://en.wikipedia.org/wiki/Todd%E2%80%93Coxeter_algorithm
 .. _Knuth-Bendix algorithm: https://en.wikipedia.org/wiki/Knuth%E2%80%93Bendix_completion_algorithm
 .. _Schreier-Sims algorithm: https://en.wikipedia.org/wiki/Schreier%E2%80%93Sims_algorithm
 .. _Konieczny: https://link.springer.com/article/10.1007/BF02573672
-.. _Lallement-McFadden: https://www.sciencedirect.com/science/article/pii/S0747717108800570 
+.. _Lallement-McFadden: https://www.sciencedirect.com/science/article/pii/S0747717108800570
 
 How to use it
 ~~~~~~~~~~~~~
@@ -42,7 +42,7 @@ See the installation instructions:
 
 .. toctree::
    :maxdepth: 1
-  
+
    install
    changelog
 
@@ -67,5 +67,5 @@ See the installation instructions:
 .. toctree::
    :caption: Further info
    :maxdepth: 1
-  
+
    authors

docs/source/install.rst

@@ -9,10 +9,6 @@
 Installation
 ============
 
-It is currently only possible to install ``libsemigroups_pybind11`` using conda
-or from  its sources. We plan to add the option of installing with ``pip`` in
-the future. 
-
 Installing with pip
 -------------------
 
@@ -28,7 +24,7 @@ Installing with conda
 ---------------------
 
 This installation method assumes that you have anaconda or miniconda installed.
-See the `getting started`_ and `miniconda download page`_ on the conda_ 
+See the `getting started`_ and `miniconda download page`_ on the conda_
 website.
 
 .. _getting started: http://bit.ly/33B0Vfs
@@ -48,9 +44,9 @@ Install ``libsemigroups_pybind11``:
 ::
 
   conda install -c conda-forge libsemigroups_pybind11
-   
-.. warning:: 
-   
+
+.. warning::
+
    At present this does not work for Macs with M1 processors.
 
 
@@ -78,12 +74,12 @@ To build ``libsemigroups_pybind11`` from a release archive:
 .. parsed-literal::
 
    curl -L -O https://github.com/libsemigroups/libsemigroups_pybind11/releases/latest/download/libsemigroups_pybind11-|libsemigroups-pybind11-version|.tar.gz
-   tar -xf libsemigroups_pybind11-|libsemigroups-pybind11-version|.tar.gz 
+   tar -xf libsemigroups_pybind11-|libsemigroups-pybind11-version|.tar.gz
    rm -f libsemigroups_pybind11-|libsemigroups-pybind11-version|.tar.gz
    cd libsemigroups_pybind11-|libsemigroups-pybind11-version|
    pip install .
 
-Building the documentation 
+Building the documentation
 --------------------------
 
 The following are required to be able to build the documentation:
@@ -97,10 +93,10 @@ the above by doing:
 
 ::
 
-    python3 -m pip3 install -r docs/requirements 
+    python3 -m pip3 install -r docs/requirements
 
 Then it ought to be possible to just run ``make doc`` in the ``libsemigroups``
-directory. 
+directory.
 
 Issues
 ------