Before generating any words, you first need a weights file. Generate one using build_weights.rb like so:
cat /path/to/dictionary | ./build_weights.rb 5 > weights.json
This will generate the weights.json file based on the words in /path/to/dictionary with a look-back of 5. The input dictionary is a collection of words, one per line. The look-back controls how much context will be used when generating a word. A look-back of one tends to generate more gibberish words, higher values will create more coherent words. 5 seems to give very good results.