Update CHANGELOG

CHANGELOG.md

@@ -21,8 +21,23 @@ Description of the upcoming release here.
 ### Fixed
 
 - [#258](https://github.com/FuelLabs/sway-libs/pull/258) Fixes incorrect instructions on how to run tests in README and docs hub.
+- [#263](https://github.com/FuelLabs/sway-libs/pull/263) Fixes `I256`'s returned bits.
+- [#263](https://github.com/FuelLabs/sway-libs/pull/263) Fixes `I128` and `I256`'s zero or "indent" value.
 
 #### Breaking
 
-- Some breaking change here 1
-- Some breaking change here 2
+- [#263](https://github.com/FuelLabs/sway-libs/pull/263) Removes the `TwosComplement` trait in favor of `WrappingNeg`.
+
+The following demonstrates the breaking change. While this example code uses the `I8` type, the same logic may be applied to the `I16`, `I32`, `I64`, `I128`, and `I256` types. 
+
+Before:
+```sway
+let my_i8 = i8::zero();
+let twos_complement = my_i8.twos_complement();
+```
+
+After:
+```sway
+let my_i8 = i8::zero();
+let wrapping_neg = my_i8.wrapping_neg();
+```