Update the "Ask for Help" section

Author: vector-of-bool

README.rst

@@ -47,6 +47,7 @@ information:
     - Examples: Windows 10 64-bit x86, Ubuntu 16.04 64-bit x86, macOS 11.0
 - C Compiler and version.
     - Examples: GCC 7.3.0, Visual Studio Community 2017, clang 3.9, XCode 9.3
+- Run CMake with ``--log-level=debug`` and ``--log-context`` for more verbose output.
 - The output of any ``cmake``, ``make``, or other commands executed during the build.
 - The text of the error you encountered.