Add 'Introduced in Catch 2.6.0.' text

docs/configuration.md

@@ -211,6 +211,7 @@ By default, Catch does not stringify some types from the standard library. This
     CATCH_CONFIG_ENABLE_OPTIONAL_STRINGMAKER // Provide StringMaker specialization for std::optional (on C++17)
     CATCH_CONFIG_ENABLE_ALL_STRINGMAKERS     // Defines all of the above
 
+> `CATCH_CONFIG_ENABLE_OPTIONAL_STRINGMAKER` was [introduced](https://github.com/catchorg/Catch2/issues/1510) in Catch 2.6.0.
 
 ## Disabling exceptions
 

docs/generators.md

@@ -1,6 +1,8 @@
 <a id="top"></a>
 # Data Generators
 
+> Introduced in Catch 2.6.0.
+
 Data generators (also known as _data driven/parametrized test cases_)
 let you reuse the same set of assertions across different input values.
 In Catch2, this means that they respect the ordering and nesting

docs/test-cases-and-sections.md

@@ -151,6 +151,8 @@ TEMPLATE_TEST_CASE( "vectors can be sized and resized", "[vector][template]", in
 
 * **TEMPLATE_PRODUCT_TEST_CASE(** _test name_ , _tags_, (_template-type1_, _template-type2_, ..., _template-typen_), (_template-arg1_, _template-arg2_, ..., _template-argm_) **)**
 
+> [Introduced](https://github.com/catchorg/Catch2/issues/1468) in Catch 2.6.0.
+
 _template-type1_ through _template-typen_ is list of template template
 types which should be combined with each of _template-arg1_ through
  _template-argm_, resulting in _n * m_ test cases. Inside the test case,