Command for generate_trie

[bkmgit]

Should the line in deepspeech.html
$ ../../native_client/generate_trie alphabet.txt lm.binary vocab.txt trie
be changed to
$ ../../native_client/generate_trie alphabet.txt lm.binary trie
generate_trie has the following output:
Usage: /../../DeepSpeech/native_client/generate_trie <lm_model> <trie_path>