Make Welcome page less wordy

[sharriet]

The Welcome page could be more succinct and content better organised.

• There is repetition, and paragraphs where bullet points would suffice. For example, the paragraph,
  "Basic experience with the Linux command line and some programming experience would be very useful..." etc.
  Could be bullet points under the 'Prerequisites' heading.
• Some confusing headings. For example, Objectives read like curricula, whereas the objectives seem to be covered in the Content section (and could just be 3-5 bullet points.)

Suggested structure:

Overview
Learning objectives
Topics
Prerequisites
Delivery

Each with just a few words or bullet points, and we could aim to follow the same structure on all courses.

[murphyqm]

Incorporating this into the new updated version!