Add example systemcard for demo

[ravimeijerrig]

Description

In this PR we:

• Add a systemcard example usecase for the demo based on the WOZ-waarde bepaling van de gemeente Oirschot.

Considerations:

• The systemcard is in Dutch, do we want that?
• The links now include a name and a link, this needs to be changed in the schema too.

Link all GitHub issues fixed by this PR.
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Resolves #

Checklist

Please check all the boxes that apply to this pull request using "x":

• I have tested the changes locally and verified that they work as expected.
• I have followed the project's coding conventions and style guidelines.
• I have rebased my branch onto the latest commit of the main branch.
• I have squashed or reorganized my commits into logical units.
• I have read, understood and agree to the Developer Certificate of Origin, which this project utilizes.

[berrydenhartog]

LGTM

[laurensWe]

LGTM :)

[berrydenhartog]

Lgtm

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[laurensWe]

Thanks for fixing the widget :) LGTM