Add Configurations.md section

Configurations.md

@@ -1229,6 +1229,48 @@ struct Dolor<T>
 }
 ```
 
+## `match_arm_forces_newline`
+
+Consistently put match arms (block based or not) in a newline.
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+
+#### `false` (default):
+
+```rust
+match x {
+    // a non-empty block
+    X0 => {
+        f();
+    }
+    // an empty block
+    X1 => {}
+    // a non-block
+    X2 => println!("ok"),
+}
+```
+
+#### `true`:
+
+```rust
+match x {
+    // a non-empty block
+    X0 => {
+        f();
+    }
+    // an empty block
+    X1 =>
+        {}
+    // a non-block
+    X2 => {
+        println!("ok")
+    }
+}
+```
+
+See also: [`wrap_match_arms`](#wrap_match_arms).
+
 ## `match_block_trailing_comma`
 
 Put a trailing comma after a block based match arm (non-block arms are not affected)