Resolve 'Edit SSH and Unity OnDemand connection documentation'

Improved clarity of Unity OnDemand and SSH pages. Common changes include changes from passive to active voice (Instead of "Configuring Username" use "Configure Username" as it implies the user makes the changes) and changes from future tense to present tense wording (Avoid using "will" unless the step takes a noticeable timeframe that is not instantaneous).

Other notes: Links should be underlined to differentiate from other bolded text. More whitespace needs to be added between steps for improved clarity (Some of the image descriptions are too close to the next step).

Closes issue #25 (closed)