Update the change log

Author: thewizardplusplus

CHANGE_LOG.md

@@ -1,7 +1,36 @@
 # Change Log
 
+## [v1.3.1](https://github.com/thewizardplusplus/luaplot/tree/v1.3.1) (2026-09-02)
+
+Using the `luatypechecks`, `luaserialization`, and `luamath` libraries for type validation, model serialization, and mathematical primitives.
+
+- models:
+  - 2D plot:
+    - storing limits as a `Range` from the [luamath](https://github.com/thewizardplusplus/luamath) library;
+    - iterating over points represented as `Vector2D(index, value)` from the [luamath](https://github.com/thewizardplusplus/luamath) library;
+    - copying mutable constructor and factory inputs;
+  - distance limit:
+    - fixing the class name from `Point` to `DistanceLimit`;
+  - 2D plot, 2D oscillogram, and distance limit:
+    - exposing a class name and a stringified representation via the [luaserialization](https://github.com/thewizardplusplus/luaserialization) library;
+    - generating a JSON Schema via the `schema()` static method;
+    - constructing an instance from serializable options via the `from_options()` static method;
+- global operations:
+  - supporting both sequences and objects with the `__index` metamethod in the `iterators` package;
+  - calculating the vertical difference between points represented as `Vector2D` objects;
+- refactoring:
+  - replacing the internal `types` package with the [luatypechecks](https://github.com/thewizardplusplus/luatypechecks) library;
+  - replacing the internal `maths` package and the CPML library with the [luamath](https://github.com/thewizardplusplus/luamath) library;
+  - adding the [luaserialization](https://github.com/thewizardplusplus/luaserialization) library;
+- misc.:
+  - adding GitHub Actions workflows for tests, linting, and documentation deployment;
+  - supporting Lua 5.1, 5.2, 5.3, 5.4, 5.5, and LuaJIT;
+  - improving the generated documentation.
+
 ## [v1.3](https://github.com/thewizardplusplus/luaplot/tree/v1.3) (2021-03-08)
 
+Selecting a value by a distance between two 2D plots/oscillograms in the specific index.
+
 - global operations:
   - selecting a value by a distance between two 2D plots/oscillograms in the specific index:
     - selecting by the specified sequential distance ranges;
@@ -15,12 +44,16 @@
 
 ## [v1.2.1](https://github.com/thewizardplusplus/luaplot/tree/v1.2.1) (2021-02-13)
 
+Describing releases of the library.
+
 - describing for releases:
   - features;
   - change log.
 
 ## [v1.2](https://github.com/thewizardplusplus/luaplot/tree/v1.2) (2021-01-10)
 
+Calculating a difference (a distance) between two 2D plots/oscillograms in the same index.
+
 - models:
   - 2D plot:
     - operations:
@@ -89,6 +122,8 @@
 
 ## [v1.1](https://github.com/thewizardplusplus/luaplot/tree/v1.1) (2021-01-03)
 
+Adding models of a 2D oscillogram and a 2D plot/oscillogram iterator.
+
 - models:
   - 2D plot:
     - storing:
@@ -179,6 +214,8 @@
 
 ## [v1.0](https://github.com/thewizardplusplus/luaplot/tree/v1.0) (2020-12-23)
 
+Major version.
+
 ### Features
 
 - models: