Modularized the tool.

rstat_tool/setup_nltk.py

@@ -0,0 +1,11 @@
+import nltk
+
+# This will download the 'vader_lexicon' dataset
+# It only needs to be run once
+try:
+    nltk.data.find('sentiment/vader_lexicon.zip')
+    print("VADER lexicon is already downloaded.")
+except LookupError:
+    print("Downloading VADER lexicon...")
+    nltk.download('vader_lexicon')
+    print("Download complete.")