[Docs] Minor copyediting of highlighting.md

Also add `apt-get` command for installing Pygments.

docs/content/extras/highlighting.md

@@ -27,24 +27,26 @@ via an embedded shortcode (see example below). If Pygments is absent from the pa
 
 ### Pygments
 
-If you have never worked with Pygments before here is a brief primer.
+If you have never worked with Pygments before, here is a brief primer.
 
-+ install python from [python.org](https://www.python.org/downloads/). Version 2.7.x is already sufficient.
-+ run `pip install Pygments` in order to install Pygments. Once installed Pygments gives you a command `pygmentize`. Make sure it sits in your path otherwise Hugo cannot find it.
++ Install Python from [python.org](https://www.python.org/downloads/). Version 2.7.x is already sufficient.
++ Run `pip install Pygments` in order to install Pygments. Once installed, Pygments gives you a command `pygmentize`. Make sure it sits in your PATH, otherwise Hugo cannot find it.
 
-Hugo gives you two options, that you can set with the variable `pygmentsuseclasses` (defaut `false`) in the `config.yaml` (or `config.toml`).
+On Debian and Ubuntu systems, you may also install Pygments by running `sudo apt-get install python3-pygments`.
 
-1. color-codes for highlighting keywords are directly inserted if `pygmentsuseclasses: false` (default). See in the example below. The color-codes depend on your choice of the `pygmentsstyle` (default `"monokai"`). You can explore the different color styles on [pygments.org](http://pygments.org/) after inserting some example code.
-2. if you choose `pygmentsuseclasses: true` Hugo includes class names in your code instead of color-codes. For class-names to be meaningful you need to include a `.css`-file in your website representing your color-scheme. You can either generate this `.css`-files according to this [description](http://pygments.org/docs/cmdline/) or download the standard ones from the [github pygments-css repository](https://github.com/richleland/pygments-css).
+Hugo gives you two options that you can set with the variable `pygmentsuseclasses` (default `false`) in `config.toml` (or `config.yaml`).
+
+1. Color-codes for highlighting keywords are directly inserted if `pygmentsuseclasses = false` (default). See in the example below. The color-codes depend on your choice of the `pygmentsstyle` (default `"monokai"`). You can explore the different color styles on [pygments.org](http://pygments.org/) after inserting some example code.
+2. If you choose `pygmentsuseclasses = true`, Hugo includes class names in your code instead of color-codes. For class-names to be meaningful, you need to include a `.css`-file in your website representing your color-scheme. You can either generate this `.css`-files according to this [description](http://pygments.org/docs/cmdline/) or download the standard ones from the [GitHub pygments-css repository](https://github.com/richleland/pygments-css).
 
 ### Usage
 Highlighting is carried out via the in-built shortcode `highlight`. `highlight` takes exactly one required parameter of language and requires a
 closing shortcode.
 
 ### Example
-If you want to highlight code you need to either fence the code with ``` according to Github flavored Markdown or each line must be preceeded by 4 spaces to identify each line as a line of code.
+If you want to highlight code, you need to either fence the code with ``` according to GitHub Flavored Markdown or preceed each line with 4 spaces to identify each line as a line of code.
 
-Not doing either will result in the text being rendered as HTML. This will prevent Pygment highlighting from working.
+Not doing either will result in the text being rendered as HTML. This will prevent Pygments highlighting from working.
 
 ```
 {{</* highlight html */>}}