Add Run.Exit option clarification (#2346)

Author: nohwnd

src/csharp/Pester/RunConfiguration.cs

@@ -63,7 +63,7 @@ public RunConfiguration() : base("Run configuration.")
             ScriptBlock = new ScriptBlockArrayOption("ScriptBlocks containing tests to be executed.", new ScriptBlock[0]);
             Container = new ContainerInfoArrayOption("ContainerInfo objects containing tests to be executed.", new ContainerInfo[0]);
             TestExtension = new StringOption("Filter used to identify test files.", ".Tests.ps1");
-            Exit = new BoolOption("Exit with non-zero exit code when the test run fails. When used together with Throw, throwing an exception is preferred.", false);
+            Exit = new BoolOption("Exit with non-zero exit code when the test run fails. Exit code is always set to `$LASTEXITCODE` even when this option is `$false`. When used together with Throw, throwing an exception is preferred.", false);
             Throw = new BoolOption("Throw an exception when test run fails. When used together with Exit, throwing an exception is preferred.", false);
             PassThru = new BoolOption("Return result object to the pipeline after finishing the test run.", false);
             SkipRun = new BoolOption("Runs the discovery phase but skips run. Use it with PassThru to get object populated with all tests.", false);