docs(CHANGES): Note Server repr update

Author: tony

CHANGES

@@ -14,6 +14,25 @@ $ pip install --user --upgrade --pre libtmux
 
 <!-- Maintainers and contributors: Insert change notes for the next release above -->
 
+### Breaking
+- Server: Add `__repr__` and set `socket_path` if none set.
+
+  Before (0.17 and below):
+
+  ```python
+  libtmux.server.Server object at ...>
+  ```
+
+  New `__repr__` (0.18+):
+
+  ```python
+  Server(socket_name=test)
+  ```
+
+  ```python
+  Server(socket_path=/tmp/tmux-1000/default)
+  ```
+
 ## libtmux 0.17.2 (2022-12-27)
 
 - Server: Move `_list_panes` and `_update_panes` to deprecated