[docs] Move the docs about ReferenceNativeSymbol in the correct file.

Author: rolfbjarne

docs/building-apps/build-items.md

@@ -309,6 +309,40 @@ the `CollectAppManifestsDependsOn` property:
 </Target>
 ```
 
+## ReferenceNativeSymbol
+
+The item group `ReferenceNativeSymbol` can be used to specify how we should
+handle a given native symbol: either ignore it, or ask the native linker to
+keep it (by passing the symbol as `-u ...` or in a symbol file to the native
+linker).
+
+There are two supported types of metadata:
+
+* `SymbolType`: either `ObjectiveCClass`, `Function` or `Field`. Used to
+  compute the complete native name of a symbol (for instance, the native
+  symbol for the Objective-C class `MyClass` is `_OBJC_CLASS_$_MyClass`,
+  while for a function `MyFunction` it's just `_MyFunction`.
+* `SymbolMode`: either `Ignore` or not set. `Ignore` means to not pass the given
+  symbol to the native linker, the default is to do so.
+
+`SymbolType` is required, while `SymbolMode` isn't.
+
+Example symbol to keep:
+
+```xml
+<ItemGroup>
+    <ReferenceNativeSymbol Include="MyClass" SymbolType="ObjectiveCClass" />
+</ItemGroup>
+```
+
+Example symbol to ignore:
+
+```xml
+<ItemGroup>
+    <ReferenceNativeSymbol Include="MyClass" SymbolType="ObjectiveCClass" SymbolMode="Ignore" />
+</ItemGroup>
+```
+
 ### SkipCodesignItems
 
 An item group that specifies files or directories in the app bundle that should not be signed.

docs/building-apps/build-properties.md

@@ -1079,37 +1079,7 @@ Only applicable to macOS and Mac Catalyst apps.
 
 ## ReferenceNativeSymbol
 
-The item group `ReferenceNativeSymbol` can be used to specify how we should
-handle a given native symbol: either ignore it, or ask the native linker to
-keep it (by passing the symbol as `-u ...` or in a symbol file to the native
-linker).
-
-There are two supported types of metadata:
-
-* `SymbolType`: either `ObjectiveCClass`, `Function` or `Field`. Used to
-  compute the complete native name of a symbol (for instance, the native
-  symbol for the Objective-C class `MyClass` is `_OBJC_CLASS_$_MyClass`,
-  while for a function `MyFunction` it's just `_MyFunction`.
-* `SymbolMode`: either `Ignore` or not set. `Ignore` means to not pass the given
-  symbol to the native linker, the default is to do so.
-
-`SymbolType` is required, while `SymbolMode` isn't.
-
-Example symbol to keep:
-
-```xml
-<ItemGroup>
-    <ReferenceNativeSymbol Include="MyClass" SymbolType="ObjectiveCClass" />
-</ItemGroup>
-```
-
-Example symbol to ignore:
-
-```xml
-<ItemGroup>
-    <ReferenceNativeSymbol Include="MyClass" SymbolType="ObjectiveCClass" SymbolMode="Ignore" />
-</ItemGroup>
-```
+See [ReferenceNativeSymbol](build-items.md#referencenativesymbols)
 
 ## RequireLinkWithAttributeForObjectiveCClassSearch