Downloading files with the wget output document (-O) set to - will print to standard output. Along with >> this can append a pre-existing file with the contents.
Use with github/gitignore to generate perfect environment gitignore files, the following will create a .gitignore perfect for Node development on macOS:
$ wget http://raw.githubusercontent.com/github/gitignore/master/Node.gitignore http://raw.githubusercontent.com/github/gitignore/master/Global/macOS.gitignore -O - >> .gitignore