Update readme

README.md

@@ -1,13 +1,26 @@
 # Minpair
 
-Generate minimal pairs (and minimal sets).
+Generate minimal pairs (and minimal sets) for US English words.
 
 > In phonology, minimal pairs are pairs of words or phrases in a particular language, spoken or signed, that differ in only one phonological element
 >
 > -- <cite>https://en.wikipedia.org/wiki/Minimal_pair</cite>
 
 ```
 >>> import minpair
->>> minpair.vowel_minpair(['AE', 'EH'])
+>>> minpair.vowel_minpair(['AE', 'EH'])[:4]
 [{'AE': 'al', 'EH': 'l'}, {'AE': 'axe', 'EH': 'x'}, {'AE': 'bad', 'EH': 'bed'}, {'AE': 'bag', 'EH': 'beg'}]
 ```
+
+# Installation
+
+```
+pip install minpair
+```
+
+# Dependencies
+
+## NLTK
+
+This package depends on a few NLTK's corpora, namely: _brown_, _cmudict_, _universal_tagset_, and _words_ corpus.
+This package will download these corpora into [NLTK data directory](https://www.nltk.org/data.html#command-line-installation) if not available.