Update upgrade guide

Author: PostScripton

docs/upgrade/3.x_to_4.x.md

@@ -145,12 +145,13 @@ Origins were completely removed from this library, so if you use them anywhere,
 🟧 The following methods no longer accept number and origin as their first and second arguments, respectively.
 
 - [`add()`](/docs/04_money/object/add.md)
+- [`subtract()`](/docs/04_money/object/subtract.md)
 - [`lessThan()`](/docs/04_money/object/lessThan.md)
 - [`lessThanOrEqual()`](/docs/04_money/object/lessThanOrEqual.md)
 - [`greaterThan()`](/docs/04_money/object/greaterThan.md)
 - [`greaterThanOrEqual()`](/docs/04_money/object/greaterThanOrEqual.md)
+- [`equals()`](/docs/04_money/object/equals.md)
 - [`rebase()`](/docs/04_money/object/rebase.md)
-- [`subtract()`](/docs/04_money/object/subtract.md)
 
 Now they have only one argument (another monetary object).