Update favorite map endpoints' responses

Author: davidbmaier

docs/live/maps/add-favorite.md

@@ -33,9 +33,7 @@ POST https://live-services.trackmania.nadeo.live/api/token/map/favorite/EgUgXeBV
 
 **Example response**:
 
-```plain
-Map favorite created
-```
+A successful response has no content and a `204` response code.
 
 Example response if the requested map does not exist:
 

docs/live/maps/remove-favorite.md

@@ -32,9 +32,7 @@ POST https://live-services.trackmania.nadeo.live/api/token/map/favorite/EgUgXeBV
 
 **Example response**:
 
-```plain
-Map favorite deleted
-```
+A successful response has no content and a `204` response code.
 
 Example response if the requested map does not exist:
 

docs/oauth/reference/favorites/add-favorite.md

@@ -37,4 +37,5 @@ POST https://api.trackmania.com/api/user/maps/favorite/add
 ```
 
 **Example response**:
-The response will be empty with a `204` response code.
+
+A successful response has no content and a `204` response code.

docs/oauth/reference/favorites/remove-favorite.md

@@ -37,4 +37,5 @@ POST https://api.trackmania.com/api/user/maps/favorite/remove
 ```
 
 **Example response**:
-The response will be empty with a `204` response code.
+
+A successful response has no content and a `204` response code.