Cleanup Documentation of Examples

[dkroenke]

Some documentation nitpicks from the examples:

• ComplexDataTypes: There is no PointData but a Point3D data type
• ObservableWaitSet: The maximum possible value of the event id is 255 so that a notify with event id 456 will result in a crash. See https://github.com/eclipse-iceoryx/iceoryx2/blob/v0.8.0/doc/release-notes/iceoryx2-v0.7.0.md#config-breaking-changes
• WaitSetMultiplexing: Same like ObservableWaitSet example

Originally posted by @dkroenke in #9 (comment)