Update LICENSE

Hi. David Lansky and Jack Clark asked me to update the GPT-2 License accordingly.

LICENSE

@@ -1,21 +1,25 @@
-MIT License
+Modified MIT License
 
-Copyright (c) 2019 OpenAI
+Software Copyright (c) 2019 OpenAI
 
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
+We don’t claim ownership of the content you create with GPT-2, so it is yours to do with as you please.  
+We only ask that you use GPT-2 responsibly and clearly indicate your content was created using GPT-2.
 
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
+MIT License Copyright (c) 2019 OpenAI 
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and 
+associated documentation files (the "Software"), to deal in the Software without restriction, 
+including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, 
+and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, 
+subject to the following conditions: 
 
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
+The above copyright notice and this permission notice shall be included 
+in all copies or substantial portions of the Software. 
+The above copyright notice and this permission notice need not be included 
+with content created by the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 
+INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE 
+OR OTHER DEALINGS IN THE SOFTWARE.