Minor documentation improvements

CONTRIBUTING.md

@@ -1,8 +1,8 @@
 # Setting up for development
 
-* Ensure that `python3` points to a version of python >= 3.8 (`python3 --version` will tell you).  If it does not, use [pyenv](https://github.com/pyenv/pyenv) to install a recent python version.
+* Ensure that `python3` points to a version of python >= 3.8 (`python3 --version` will tell you).  If it does not, use [pyenv](https://github.com/pyenv/pyenv) to both install a recent python version and make it your current python.
 
-* There are two wrappers (`poetryw` and `toxw`) that install and run the correct versions of [poetry](https://python-poetry.org) and [tox](https://tox.wiki) for you; respectively.
+* There are two wrappers (`poetryw` and `toxw`) that install and run the correct versions of [poetry](https://python-poetry.org) and [tox](https://tox.wiki) for you.
 
 * Run poetry to install dependencies:
 
@@ -21,7 +21,7 @@ See the [poetry docs](https://python-poetry.org/docs) for more.
 # Running tests
 
 ```
-./poetryw run pytest tests
+./poetryw run pytest
 ```
 
 ...or using [tox](https://tox.readthedocs.io/):
@@ -32,7 +32,7 @@ See the [poetry docs](https://python-poetry.org/docs) for more.
 
 # Linting and formatting
 
-Code-style is enforced using [black](https://black.readthedocs.io/).  Linting is automatically applied when tox runs tests; if linting fails, you can fix it with:
+Code-style is enforced using [black](https://black.readthedocs.io/) and [flake8](https://flake8.pycqa.org/); import optimisation is handled by [isort](https://pycqa.github.io/isort/) and [autoflake](https://pypi.org/project/autoflake/).  Linting is automatically applied when tox runs tests; if linting fails, you can fix trivial problems with:
 
 ```
 ./toxw -e format