note about fsi extensions

replacing PR dotnet#21673

Author: smoothdeveloper

docs/fsharp/tools/fsharp-interactive/index.md

@@ -84,6 +84,9 @@ F# scripting is natively supported in [Visual Studio](../../get-started/get-star
 
 ## Referencing packages in F# Interactive
 
+> [!NOTE]
+> Package management system is extensible, read more [about other extensions](https://github.com/dotnet/fsharp/tree/main/src/fsharp/Microsoft.DotNet.DependencyManager).
+
 F# Interactive supports referencing NuGet packages with the `#r "nuget:"` syntax and an optional version:
 
 ```fsharp
@@ -128,6 +131,8 @@ You can specify as many package references as you like in a script.
 > [!NOTE]
 > There's currently a limitation for scripts that use framework references (e.g.`Microsoft.NET.Sdk.Web` or  `Microsoft.NET.Sdk.WindowsDesktop`). Packages like Saturn, Giraffe, WinForms are not available. This is being tracked in issue [#9417](https://github.com/dotnet/fsharp/issues/9417).
 
+Read more about [package management extensibility and other extensions](https://github.com/dotnet/fsharp/tree/main/src/fsharp/Microsoft.DotNet.DependencyManager).
+
 ## Referencing assemblies on disk with F# interactive
 
 Alternatively, if you have an assembly on disk and wish to reference that in a script, you can use the `#r` syntax to specify an assembly. Consider the following code in a project compiled into `MyAssembly.dll`: