chore(README): add Dish Decision Maker example
chore(README): add Dish Decision Maker example

- add link to spin examples
- add link to DMN examples
- add dish decision maker example

related to #CAM-5032
ingorichtsmeier/camunda-bpm-examples,skjolber/camunda-bpm-examples,camunda/camunda-bpm-examples,ingorichtsmeier/camunda-bpm-examples,skjolber/camunda-bpm-examples,camunda/camunda-bpm-examples,camunda/camunda-bpm-examples,camunda/camunda-bpm-examples,skjolber/camunda-bpm-examples,ingorichtsmeier/camunda-bpm-examples