twente-microbubblesim: link the CC BY 4.0 deed in the data card

Syncs the twente-microbubblesim card on the Hub with the reviewed state on GitHub (open-h/OpenH-RF).

One fix: the licence section linked `LICENCE`, which is not a file in either repository, so the link was dead. It now links the CC BY 4.0 deed. Nothing else changed.

Files changed: 1.

```
~ twente-microbubblesim/README.md
```

twente-microbubblesim/README.md

@@ -43,7 +43,7 @@ simulated data, not clinical, phantom, or in-vivo animal data.
 ## License / Terms of Use
 
 This dataset is released under the Creative Commons Attribution 4.0
-International license (CC BY 4.0). See [LICENCE](LICENCE). The contributors
+International license (CC BY 4.0). See [creativecommons.org/licenses/by/4.0](https://creativecommons.org/licenses/by/4.0/). The contributors
 confirm that the simulated RF outputs, bubble ground truth, pulse waveforms,
 calibrated P4-1 inputs, and incorporated assets used to produce this dataset
 are cleared for public redistribution under CC BY 4.0, consistent with the