Document Publish UseCurrentRuntime

Same as #31970 but for publish!

Author: nagilson

docs/core/tools/dotnet-publish.md

@@ -21,8 +21,8 @@ dotnet publish [<PROJECT>|<SOLUTION>] [-a|--arch <ARCHITECTURE>]
     [--no-restore] [--nologo] [-o|--output <OUTPUT_DIRECTORY>]
     [--os <OS>] [-r|--runtime <RUNTIME_IDENTIFIER>]
     [--sc|--self-contained [true|false]] [--no-self-contained]
-    [-s|--source <SOURCE>] [-v|--verbosity <LEVEL>]
-    [--version-suffix <VERSION_SUFFIX>]
+    [-s|--source <SOURCE>] [--use-current-runtime, --ucr [true|false]]
+    [-v|--verbosity <LEVEL>] [--version-suffix <VERSION_SUFFIX>]
 
 dotnet publish -h|--help
 ```
@@ -182,6 +182,10 @@ For more information, see the following resources:
 
 [!INCLUDE [verbosity](../../../includes/cli-verbosity-minimal.md)]
 
+- **`--use-current-runtime, --ucr [true|false]`**
+
+  Sets the `RuntimeIdentifier` to a platform portable `RuntimeIdentifier` based on the one of your machine. This happens implicitly with properties that require a `RuntimeIdentifier`, such as `SelfContained`, `PublishAot`, `PublishSelfContained`, `PublishSingleFile`, and `PublishReadyToRun`. If the property is set to false, that implicit resolution will no longer occur.
+
 - **`--version-suffix <VERSION_SUFFIX>`**
 
   Defines the version suffix to replace the asterisk (`*`) in the version field of the project file.