Invalid link in the docs, in the recursive section.

### Describe the issue or suggestion

On this page:
https://github.com/dotnet/docs/blob/main/docs/fsharp/language-reference/functions/recursive-functions-the-rec-keyword.md

The section 'Mutually Recursive Functions' has an invalid link to the sample code.

---
#### Document Details

⚠ *Do not edit this section. It is required for learn.microsoft.com ➟ GitHub issue linking.*

* ID: 029d87c5-6502-8151-c903-dec53a570b0a
* Version Independent ID: 4aececf7-7876-3bc1-f722-1004b25fe05d
* Content: [Recursive Functions: The rec Keyword - F#](https://learn.microsoft.com/en-us/dotnet/fsharp/language-reference/functions/recursive-functions-the-rec-keyword)
* Content Source: [docs/fsharp/language-reference/functions/recursive-functions-the-rec-keyword.md](https://github.com/dotnet/docs/blob/main/docs/fsharp/language-reference/functions/recursive-functions-the-rec-keyword.md)
* Service: **dotnet-fsharp**
* GitHub Login: @KathleenDollard
* Microsoft Alias: **kdollard**