update changelog [skip ci]

Signed-off-by: DONNOT Benjamin <[email protected]>

Author: BDonnot

CHANGELOG.rst

@@ -108,10 +108,13 @@ Native multi agents support:
 - [FIXED] issue 713
 - [FIXED] pandapower 3 compatibility
 - [ADDED] compatibility with numpy 2, scipy >= 1.14 and python 3.13
+- [ADDED] some examples showing how grid2op can be use to solve some specific 
+  kind of problem (related to N-1 safety and phase shift transformer).
 - [IMPROVED] clarity of the `failed_redispatching` key of the `info` returned value
   of the `env.step` function (previously called `is_redispatching_illegal` which 
   was not clear)
 - [IMPROVED] way to load back class stored in json format
+- [IMPROVED] the way the Observation class can be overriden
 
 [1.11.0] - 2025-04-14
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