Remove outdated reference to submodules
Remove outdated reference to submodules

We stopped using submodules when moving to Go: https://github.com/rainforestapp/rainforest-cli/commit/c80574b7a7d8c8fc76ca6fb454a7b2cbd16c6e04#diff-8903239df476d7401cf9e76af0252622

rainforestapp/rainforest-cli,rainforestapp/rainforest-cli