Docs: fix rendering

[queil]

Describe the bug
At the moment docs generation is broken.

To Reproduce

1. Run ./build.sh ReleaseDocs

Error:

Fatal error: System.Exception: error while formatting file /home/queil/gh/FsConfig/docsSrc/content/index.fsx. Errors are:
seq
  [SourceError
     ((105, 2), (105, 5), ErrorKind.Error,
      "The block following this 'let' is unfinished. Every code block is an expression and must have a result. 'let' cannot be the final code element in a block. Consider giving this block an explicit result.");
   SourceError
     ((48, 21), (48, 30), ErrorKind.Error,
      "The namespace or module 'GetStream' is not defined.");
   SourceError
     ((49, 6), (49, 12), ErrorKind.Error,
      "The record label 'ApiKey' is not defined.");
   SourceError
     ((83, 2), (83, 12), ErrorKind.Error,
      "The type 'Convention' is not defined."); ...]
   at Microsoft.FSharp.Core.PrintfModule.PrintFormatToStringThenFail@1639.Invoke(String message) in F:\workspace\_work\1\s\src\fsharp\FSharp.Core\printf.fs:line 1639

It seems (*** do-not-eval-file ***) is not respected.

Expected behavior
A new version of docs gets published to the docs dir.