Add formatter to versioning

docs/versioning.md

@@ -9,30 +9,38 @@ Ruff uses a custom versioning scheme that uses the **minor** version number for
 - A deprecated option or feature is removed
 - Configuration changes in a backwards incompatible way
     - This _may_ occur in minor version changes until `1.0.0`, however it should generally be avoided.
-- A rule is promoted to stable
 - Support for a new file type is promoted to stable
 - Support for an end-of-life Python version is dropped
-- The behavior of a stable rule is changed
-    - The scope of a stable rule is significantly increased
-    - The intent of the rule changes
-    - Does not include bug fixes that follow the original intent of the rule
-- Stable rules are added to the default set
-- Stable rules are removed from the default set
-- A safe fix for a rule is promoted to stable
+- Linter:
+    - A rule is promoted to stable
+    - The behavior of a stable rule is changed
+        - The scope of a stable rule is significantly increased
+        - The intent of the rule changes
+        - Does not include bug fixes that follow the original intent of the rule
+    - Stable rules are added to the default set
+    - Stable rules are removed from the default set
+    - A safe fix for a rule is promoted to stable
+- Formatter: 
+     - The stable style changed
 
 **Patch** version increases will occur when:
 
 - Bugs are fixed, _including behavior changes that fix bugs_
-- An unsafe fix for a rule is added
-- A safe fix for a rule is added in preview
-- The scope of a rule is increased in preview
-- A fix’s applicability is demoted
-- A new configuration option is added
-- A rule is added in preview
-- The behavior of a preview rule is changed
+- A new configuration option is added in a backwards compatible way (no formatting changes or new lint errors)
 - Support for a new Python version is added
 - Support for a new file type is added in preview
 - An option or feature is deprecated
+- Linter:
+    - An unsafe fix for a rule is added
+    - A safe fix for a rule is added in preview
+    - The scope of a rule is increased in preview
+    - A fix’s applicability is demoted
+    - A rule is added in preview
+    - The behavior of a preview rule is changed
+- Formatter:
+    - The stable style changed to prevent invalid syntax, changes to the program's semantics, or removal of comments
+    - The preview style changed
+
 
 ## Preview mode