generate-README.rb: remove dependency to YAML gem
generate-README.rb: remove dependency to YAML gem

At the cost of some quotes and commas.

Background:
https://github.com/ps-mr/ilc/issues/41#issuecomment-21932291

Old-commit-hash: 576c1faa41841d11efdffb2a51f8c31b28928785

inc-lc/ilc-agda