[docs] Update documentation with buildUmlMetaInfo() function

Author: nsk90

docs/pages/export.md

@@ -64,15 +64,16 @@ See [Mermaid nested states export sample](https://github.com/nsk90/kstatemachine
 
 ## Controlling export output
 
-To beautify and enrich export output, you can use `UmlMetaInfo` for both `IState` and `Transition`:
+To beautify and enrich export output, you can use `UmlMetaInfo` for both `IState` and `Transition`. It can be built 
+with `buildUmlMetaInfo()` function:
 
 ```kotlin
 state("State1") {
-    metaInfo = UmlMetaInfo(
-        umlLabel = "State 1 long label",
-        umlStateDescriptions = listOf("Description 1", "Description 2"),
-        umlNotes = listOf("Note 1", "Note 2"),
-    )
+    metaInfo = buildUmlMetaInfo {
+        umlLabel = "State 1 long label"
+        umlStateDescriptions = listOf("Description 1", "Description 2")
+        umlNotes = listOf("Note 1", "Note 2")
+    }
 }
 ```
 

docs/pages/meta_information.md

@@ -19,6 +19,7 @@ The library provides `metaInfo` property for `IState` and `Transition` types.
 This mechanism is extendable and users may add their own `MetaInfo` sub interfaces/classes if necessary.
 Currently, the only standard implementation is `UmlMetaInfo` which is useful for export feature.
 See [controlling export output](https://kstatemachine.github.io/kstatemachine/pages/export.html#controlling-export-output).
+You can build it using `buildUmlMetaInfo()` function.
 
 {: .note }
 `MetaInfo` considered to be immutable data by design