Update docs/guide/from-2021b-to-2022a.md

Co-authored-by: Stefania Pedrazzi <[email protected]>

docs/guide/from-2021b-to-2022a.md

@@ -40,7 +40,7 @@ In any case, it is important to understand how Webots nodes are affected by the
 | [Receiver](../reference/receiver.md) | <img src="https://render.githubusercontent.com/render/math?math=\color{gray}\large(-\frac{\pi}{2}, 0, -\frac{\pi}{2})"> | A2 |
 | [Connector](../reference/connector.md) | <img src="https://render.githubusercontent.com/render/math?math=\color{gray}\large(-\frac{\pi}{2}, 0, -\frac{\pi}{2})"> | A2 |
 | [TouchSensor](../reference/touchsensor.md) | <img src="https://render.githubusercontent.com/render/math?math=\color{gray}\large(-\frac{\pi}{2}, 0, -\frac{\pi}{2})"> | A2 |
-| Webots PROTOs | <img src="https://render.githubusercontent.com/render/math?math=\color{gray}\large(-\frac{\pi}{2}, 0, \frac{\pi}{2})">, but there are numerous exceptions to this rule as the protos did not followed any specific convention any now | C |
+| Webots PROTOs | <img src="https://render.githubusercontent.com/render/math?math=\color{gray}\large(-\frac{\pi}{2}, 0, \frac{\pi}{2})">, but there are numerous exceptions to this rule as the PROTOs did not followed any specific convention any now | C |
 
 ### Automatic Conversion to ENU FLU