move @types/tmp to dependencies

[ehaynes99]

Currently, the package file has "@types/tmp": "^0.2.0", under devDependencies. However, the types in types.d.ts directly export members of tmp. Unless the consuming app also installs @types/tmp, those types are all missing. This prevents auto-suggestion, but more importantly, prevents the type checker from being able to enforce the parameters.

Re-exported types should be in dependencies instead.

E.g. DirOptions here can't be type checked:

import { FileOptions, DirOptions, TmpNameOptions } from "tmp";
// ...
export function dir(options?: DirOptions): Promise<DirectoryResult>;

results in: