Minor improvements to dev tools (#338)

Just very minor sentence/language improvements here.

Author: dstansby

docs/pages/dev.md

@@ -5,18 +5,18 @@ layout: default
 
 # Virtual environments
 
-| Name                                                     | Short description                                                                   | 🚦  |
-| -------------------------------------------------------- | ----------------------------------------------------------------------------------- | :-: |
-| [Conda](https://docs.conda.io/projects/conda/en/stable/) | Conda quickly installs, runs, and updates packages and their dependencies.          | 🟢  |
-| [pipenv](https://pipenv.pypa.io/en/latest/)              | A tool that automatically creates and manages a virtualenv for your projects.       | 🟠  |
-| [pyenv](https://github.com/pyenv/pyenv)                  | A tool that lets you easily switch between multiple versions of Python.             | 🟠  |
-| [virtualenv](https://virtualenv.pypa.io/en/latest/)      | A tool to create isolated Python environments which offers more features than venv. | 🟠  |
-| [venv](https://docs.python.org/3/library/venv.html)      | A tool to create isolated Python environments.                                      | 🔴  |
+| Name                                                     | Short description                                                         | 🚦  |
+| -------------------------------------------------------- | ------------------------------------------------------------------------- | :-: |
+| [Conda](https://docs.conda.io/projects/conda/en/stable/) | Installs, runs, and updates packages and their dependencies.              | 🟢  |
+| [pipenv](https://pipenv.pypa.io/en/latest/)              | Automatically creates and manages a virtualenv for your projects.         | 🟠  |
+| [pyenv](https://github.com/pyenv/pyenv)                  | Lets you easily switch between multiple versions of Python.               | 🟠  |
+| [virtualenv](https://virtualenv.pypa.io/en/latest/)      | Creates isolated Python environments, and offers more features than venv. | 🟠  |
+| [venv](https://docs.python.org/3/library/venv.html)      | Creates isolated Python environments.                                     | 🔴  |
 
 # Other
 
-| Name                                                        | Short description                            | 🚦  |
-| ----------------------------------------------------------- | -------------------------------------------- | :-: |
-| [jedi](https://jedi.readthedocs.io/en/latest/)              | Refactoring and autocompletion used in IDEs. | 🟢  |
-| [rope](https://rope.readthedocs.io/en/latest/overview.html) | Refactoring library.                         |     |
-| [tqdm](https://pypi.org/project/tqdm/2.2.3/)                | Progress bar for loops.                      | 🟢  |
+| Name                                                        | Short description                                                                      | 🚦  |
+| ----------------------------------------------------------- | -------------------------------------------------------------------------------------- | :-: |
+| [jedi](https://jedi.readthedocs.io/en/latest/)              | Refactoring and autocompletion used in for integrated development environments (IDEs). | 🟢  |
+| [rope](https://rope.readthedocs.io/en/latest/overview.html) | Refactoring library.                                                                   |     |
+| [tqdm](https://pypi.org/project/tqdm/2.2.3/)                | Progress bar for loops.                                                                | 🟢  |