Why is there a separate package just for the eslint config?
Good question. ESLint is in some ways truly insane, and in this case the only way to share configs from a node_module is if that node_module is prefixed with the name eslint-config.
We'll try and mask this so devs don't need to know about this weird artifact of eslint config lookups, but if you're editing the eslint config, you will need to publish both @manifoldxyz/eslint-config and @manifoldxyz/lint-configs.