Change button sequence

[kaena83]

Currently

The sequence of the buttons does not reflect the user workflow. Therefore it might be difficult for users to understand what they are supposed to do when using Metafacture Playground for the first time.

Suggestion

Alter the sequence of the buttons, e.g.

1. Load Examples
2. Import Workflow
3. Process
4. Export Workflow
5. Clear
6. Share

In addition, the button "Share" could be visually seperated a bit from the rest (e.g. right hand corner or so).

[katauber]

functional review:
code review: @fsteeg