Switched application's arrangement in Recommendations & Optional Tasks

[HellBringer419]

This fix is a follow-up to last PR #297 Some applications have been arranged differently.

• Dropbox is now under Getting Started/Optional Tasks
• Snap Applications is the end of the recommendations list
• Nemo Share & Nemo Preview have exchanged spots

Reviewer: @fossfreedom Please inform Mauro when merged. Thanks

[fossfreedom]

Lets merge these - Mauro will confirm when the edge snap is built.