build as a submodule is complicated

[yoni386]

cloning the repro https://github.com/whoshuu/cpr-example is working and using the global curl.

why mongoose is included? can you make the fork thin and maybe add more info how include it without clone the full repo https://github.com/whoshuu/cpr-example
More info how use the global curl (cmake guild).