Update repository reference and instructions. (#21)

* Update repository reference and instructions.

* Minor markdown linting

README.md

@@ -1,8 +1,8 @@
 # ubuntu-mate-guide
 
-**A guide to Ubuntu MATE**
+## A guide to Ubuntu MATE
 
-Written in DocBook XML V4.5 format [DocBook](http://docbook.org/xml/4.5/docbookx.dtd) - a semantic markup language for technical documentation. 
+Written in DocBook XML V4.5 format [DocBook](http://docbook.org/xml/4.5/docbookx.dtd) - a semantic markup language for technical documentation.
 
 ## History
 
@@ -13,64 +13,83 @@ With Ubuntu MATE release 18.10 the documentation has been expanded significantly
 The most recent update to the guide incorporates new applications and features of **Ubuntu MATE release 22.04**.
 
 ----------
+
 ## Translations
 
-The documentation is only in English at the moment. 
+The documentation is only in English at the moment.
 
 ----------
+
 ## Setting up the DocBook Writing Environment
 
-First, as long as you have a text editor, you have all the tools you need to create the documentation. 
+First, as long as you have a text editor, you have all the tools you need to create the documentation.
 
-Most text editors, like **Pluma**, have the ability to set the "Highlight Mode" to provide syntax highlighting for DocBook XML files. When using **Pluma**, you select *View > Highlight Mode > Markup > DocBook*. 
+Most text editors, like **Pluma**, have the ability to set the "Highlight Mode" to provide syntax highlighting for DocBook XML files. When using **Pluma**, you select *View > Highlight Mode > Markup > DocBook*.
 
 When you save the file with the `.docbook` extension, the next time you open the file in the text editor, it will be highlighted correctly so that you can continue editing.
 
 ### Clone the files
 
-    mkdir ~/ubuntu-mate-guide
-    cd ~/ubuntu-mate-guide
-    git clone [email protected]:ubuntu-mate/ubuntu-guide.git
+```shell
+git clone [email protected]:ubuntu-mate/ubuntu-mate-guide.git
+```
+
+or if you prefer to use `gh`
+
+```shell
+gh repo clone ubuntu-mate/ubuntu-mate-guide
+```
 
 ----------
+
 ## Reducing the size of graphics files
 
 Graphics files contained in the /apps and /figures folders. To reduce the size of png and jpg files, use these two commands:
-``` 
+
+```shell
 jpegoptim --strip-all -t *.jpg
 optipng -strip all -o7 *.png
 ```
 
 ----------
+
 ## Testing the index.docbook file
 
 The entire ubuntu-mate-guide is contained in the file `index.docbook`, with graphics files contained in the /apps and /figures folders. To test the file, open it in **Yelp**:
 
-``` 
+```shell
 yelp index.docbook
 ```
 
 ----------
+
 ## File location in Ubuntu MATE
 
-The `index.docbook` file is simply placed in this location `/usr/share/help/C/ubuntu-mate-guide/index.dobook`. Translations are placed in `/usr/share/help/<language>/ubuntu-mate-guide/index.docbook` where `<language>` is the standard two-letter language code.
+The `index.docbook` file is simply placed in this location:
+
+`/usr/share/help/C/ubuntu-mate-guide/index.docbook`
+
+ Translations are placed in `/usr/share/help/<language>/ubuntu-mate-guide/index.docbook` ( where `<language>` is the standard two-letter language code).
 
 ----------
+
 ## PDF Conversion
 
 Install these command-line utilities: `pandoc` `texlive-xetex` and `texlive-fonts-extra` (and dependencies) from the Ubuntu MATE repositories and use **pandoc** to convert the docbook file to markdown and then from markdown to pdf:
 
-```
+```shell
 pandoc -f docbook -t markdown -s index.docbook -o UMGuide.md
 pandoc UMGuide.md  --pdf-engine=xelatex -o UMGuide.pdf
 ```
 
 ----------
+
 ## HTML Conversion
 
 The `pandoc` application is also used to create the online publication of the Ubuntu MATE Guide at [http://guide.ubuntu-mate.org](http://guide.ubuntu-mate.org).
 
-Further information can be found here: 
+Further information can be found here:
+
 [https://github.com/ubuntu-mate/guide.ubuntu-mate.org](https://github.com/ubuntu-mate/guide.ubuntu-mate.org)
 
 An HTML file can be created from the markdown file with this command: