[docs] add openssl to windows docs

Signed-off-by: crueter <crueter@eden-emu.dev>

docs/build/Windows.md

@@ -10,6 +10,7 @@ On Windows, all library dependencies are automatically included within the `exte
   * **[CMake](https://cmake.org/download/)** - Used to generate Visual Studio project files. Does not matter if either 32-bit or 64-bit version is installed.
   * **[Vulkan SDK](https://vulkan.lunarg.com/sdk/home#windows)** - **Make sure to select Latest SDK.**
     - A convenience script to install the latest SDK is provided in `.ci\windows\install-vulkan-sdk.ps1`.
+  * **[OpenSSL](https://slproweb.com/products/Win32OpenSSL.html)** - You are recommended to keep the default install location, otherwise you will have to specify a custom OpenSSL root.
 
   ![2](https://i.imgur.com/giDwuTm.png)
 

externals/CMakeLists.txt

@@ -4,6 +4,9 @@
 # SPDX-FileCopyrightText: 2016 Citra Emulator Project
 # SPDX-License-Identifier: GPL-2.0-or-later
 
+# TODO(crueter): A lot of this should be moved to the root.
+# otherwise we have to do weird shenanigans with library linking and stuff
+
 # cpm
 include(CPMUtil)