bump changelog to 50.13-r4

changelog.txt

@@ -28,6 +28,16 @@ Template for new versions:
 
 ## New Tools
 
+## New Features
+
+## Fixes
+
+## Misc Improvements
+
+## Removed
+
+# 50.13-r4
+
 ## New Features
 - `gui/journal`: new automatic table of contents. add lines that start with "# ", like "# Entry for 502-04-02", to add hyperlinked headers to the table of contents
 
@@ -53,8 +63,6 @@ Template for new versions:
 - `list-waves`: can now display information about specific migration waves (e.g. ``list-waves 0`` to identify your starting 7 dwarves)
 - `allneeds`: display distribution of needs by how severely they are affecting the dwarf
 
-## Removed
-
 # 50.13-r3
 
 ## New Tools