[v2.6.2] Error in documentation

The option in the documentation is wrong. https://github.com/CLIUtils/CLI11/blob/37bb6edc5317e99af72ef48405e65d9ca5218861/book/chapters/installation.md?plain=1#L203 This is the actually used value. https://github.com/CLIUtils/CLI11/blob/37bb6edc5317e99af72ef48405e65d9ca5218861/tests/CMakeLists.txt#L369