Docs: declare required Windows 10 SDK and Platform Toolset for building MKL

appveyor.yml

@@ -2,7 +2,7 @@ image: Visual Studio 2017
 init:
    - git config --global core.autocrlf true
 install:
-   # Download .NET Core SDK 3.0.100 and add to PATH
+   # Download .NET Core SDK 3.1.101 and add to PATH
    - ps: $urlCurrent = "https://dotnetcli.azureedge.net/dotnet/Sdk/3.1.101/dotnet-sdk-3.1.101-win-x64.zip"
    - ps: $env:DOTNET_INSTALL_DIR = "$pwd\.dotnetsdk"
    - ps: mkdir $env:DOTNET_INSTALL_DIR -Force | Out-Null

docs/content/Build.md

@@ -146,6 +146,10 @@ The build expects that either Intel Parallel Studio 2020 (with the Intel Compile
 or Intel Math Kernel Library 2020 is installed. If you run into an error with `mkl_link_tool.exe`
 you may need to patch a targets file, see [MKL 2020.1, VS2019 linking bug ](https://software.intel.com/en-us/forums/intel-math-kernel-library/topic/851578).
 
+The build is targeting `Windows 10 SDK (10.0.17763.0)` and the `v141` platform toolset,
+both of which can be installed as individual components in the Visual Studio Installer,
+together with the `Desktop development with C++` workload.
+
 The build can then be triggered by calling:
 
     ./build.sh MklWinBuild  // build both 32 and 64 bit variants