Windows build with openssl option requires perl
Add Perl into `Additional Requirements` list for folks who want to build it on Windows with no schannel support / or with openssl explicitly.
@@ -94,6 +94,7 @@ Note at minimum CMake 3.16 is required. Instructions for installing a the newest
### Additional Requirements on Windows
* [CMake](https://cmake.org/)
+ * [Perl](https://www.perl.org/get.html) optional (required for OpenSSL build)
* [Visual Studio 2019](https://www.visualstudio.com/vs/) or higher
* Latest [Windows Insider](https://insider.windows.com/en-us/) builds
