Fixes dotnet#42838 (#5010)

Co-authored-by: Mark Osborn <[email protected]>

Author: ozziepeeps

xml/Microsoft.Extensions.DependencyInjection/OptionsServiceCollectionExtensions.xml

@@ -170,7 +170,7 @@
         <typeparam name="TOptions">The options type to be configured.</typeparam>
         <param name="services">The <see cref="T:Microsoft.Extensions.DependencyInjection.IServiceCollection" /> to add the services to.</param>
         <param name="configureOptions">The action used to configure the options.</param>
-        <summary>Registers an action used to configure a particular type of options. These are run before <see cref="M:Microsoft.Extensions.DependencyInjection.OptionsServiceCollectionExtensions.PostConfigure``1(Microsoft.Extensions.DependencyInjection.IServiceCollection,System.Action{``0})" />.</summary>
+        <summary>Registers an action used to configure a particular type of options once during startup. This is run before <see cref="M:Microsoft.Extensions.DependencyInjection.OptionsServiceCollectionExtensions.PostConfigure``1(Microsoft.Extensions.DependencyInjection.IServiceCollection,System.Action{``0})" />. Updates to the configuration does not invoke the action again.</summary>
         <returns>The <see cref="T:Microsoft.Extensions.DependencyInjection.IServiceCollection" /> so that additional calls can be chained.</returns>
         <remarks>To be added.</remarks>
       </Docs>