Bug in README

[suryanshup]

README provides an example for

Code-generate schema + dependencies:

% wdlc -I ~/openweave-schema-vendor-nest -I ~/openweave-schema-vendor-common --gen weave-device-cpp --gen_dependencies --output ./build ~/openweave-schema-vendor-nest/nest/resource/nest_detect_resource.proto ~/openweave-schema-vendor-nest/nest/resource/nest_guard_resource.proto

--gen_dependencies is not a valid parameter. README needs to be updated to use the correct parameter (--gen-dependencies).