Corrected run command and updated instruction text

README.md

 # Building Mahara docs
 
-The Mahara User Manual is:
+The Mahara Manual is:
 
 - written using [reStructuredText](http://docutils.sourceforge.net/rst.html)
 - built using [Sphinx](http://www.sphinx-doc.org/)
-  - with a docker builder
+- with a docker builder
 
 
 # Quickstart
 
-Run one of the commands below to build the docs. The first command only builds english.
-The second builds all translations(and takes longer).
+Run one of the commands below from the main folder to build the docs. 
+The first command only builds English. The second builds all translations
+(and takes longer).
 
 ```
   docker run -v $(pwd)/:/home/docbuilder/source mahara/docbuilder TRANSLATIONS=en html
   docker run -v $(pwd)/:/home/docbuilder/source mahara/docbuilder html
 ```
 
-The built docs will be in the `build/html` directory(on your host machine.
+The built docs will be in the `build/html` directory (on your host machine).
 
 ## Pre-requisites
 
@@ -32,7 +33,7 @@ If docker is available you can build the docbuilder image on Linux with:
 
 ```
 cd manual-build
-docker build --build-arg IMAGE_UID=`id -u` --build-arg IMAGE_UID=`id -g` --tag mahara/docbuilder .
+docker build --build-arg IMAGE_UID=`id -u` --build-arg IMAGE_GID=`id -g` --tag mahara/docbuilder .
 ```
 
 The `mahara/docbuilder` image is based on a debian docker image with additional