Add license

README.md

@@ -14,6 +14,8 @@ python3 ttc2ttf.py SourceHanSans.ttc
 ./wordfreq.py -i example.in -o example.png -p n,ne -f SourceHanSans10.ttf -t 60
 ```
 
+You should use Source Han Sans font under the terms of SIL Open Font License 1.1.
+
 ## Parts of speech
 
 See `pos.txt`, [origin gist](https://gist.github.com/hscspring/c985355e0814f01437eaf8fd55fd7998) by [hscspring](https://gist.github.com/hscspring).

wordfreq.py

@@ -1,5 +1,15 @@
 #!/usr/bin/env python3
 
+
+#------------------------------------------------------------------------#
+# "THE BEER-WARE LICENSE" (Revision 42):                                 #
+# <xry111@mengyan1223.wang> wrote this file.  As long as you retain this #
+# notice you can do whatever you want with this stuff. If we meet some   #
+# day, and you think this stuff is worth it, you can buy me a beer in    #
+# return.                                                                #
+#                                                       Xi Ruoyao        #
+#------------------------------------------------------------------------#
+
 import argparse
 import jieba
 import jieba.posseg as posseg