Added docs on deprecation

Author: krichardsson

cflib/crazyflie/mem/trajectory_memory.py

@@ -169,12 +169,12 @@ def __init__(self, id, type, size, mem_handler):
         # elements in the same trajectory.
         self.trajectory = []
 
-    # Deprecated. replaced by self.trajectory
+    # Deprecated (removed after August 2023). replaced by self.trajectory
     @property
     def poly4Ds(self):
         return self.trajectory
 
-    # Deprecated. replaced by self.trajectory
+    # Deprecated (removed after August 2023). replaced by self.trajectory
     @poly4Ds.setter
     def poly4Ds(self, trajectory):
         self.trajectory = trajectory

docs/development/apis_versions_deprecation.md

@@ -0,0 +1,11 @@
+---
+title: APIs, versions and deprecations
+page_id: api-deprecation
+---
+
+There are a number of APIs in the Crazyflie eco system on multiple levels, some might be obvious while others are a bit
+more subtle. Some of the APIs are documented and versioned while there is room for improvement in other cases.
+
+Please see the section in the firmware documentation related to
+[APIs and versions](https://www.bitcraze.io/documentation/repository/crazyflie-firmware/master/development/apis_versions_deprecation/)
+for more information.