Updated CHANGES.md.

CHANGES.md

 Changes
 =======
 
-2.0 WIP
--------
-
-Major refactor
-
-Before, in calculating close contacts, those less than 2.5 not included in list of less than 4 (no redundancies). Now listed again (so redundancies).
-
-Added output_json option.
-
-Created BINANA.js library, and made web app.
+2.0
+---
 
-Changed name of development branch to `main`.
+1. We have refactored the code to make it more modular. BINANA still works as a
+   command-line program, but it now also functions as a Python library, allowing
+   others to import BINANA's various functions into their scripts.
+2. BINANA now works with Python3. Python2 is no longer officially supported.
+3. BINANA can now output analyses to the JSON format, improving compatibility
+   with other analysis programs.
+4. We have ported the Python codebase to JavaScript using the [Transcrypt
+   transpiler](https://www.transcrypt.org/). Others can now access the BINANA.js
+   library from their web apps.
+5. To demonstrate JavaScript use, we created a [web
+   app](http://durrantlab.com/binana/) that leverages the BINANA.js library. The
+   Git repository includes the web-app source code.
+6. The BINANA 2.0 interaction criteria are identical to the original version,
+   except for close and closest contacts. Previously, these two interactions
+   were mutually exclusive (i.e., those protein/ligand atom pairs that were
+   close enough to be categorized as "closest" were not also considered to be
+   "close"). In BINANA 2.0, all closest contacts are also close.
+7. We created a [documentation website](http://durrantlab.com/apps/binana/docs/)
+   to further improve BINANA usability.
+8. We changed the name of the development branch from `master` to `main`.
+9. We release BINANA 2.0 under a more permissive license than previous versions
+   (Apache License, Version 2.0). 
 
 1.3
 ---
 
-1. BINANA is now requires Python3. Python2 support has been discontinued.
+1. BINANA now requires Python3. Python2 support has been discontinued.
 2. Added documentation files in MarkDown format.
 3. Updated code formatting some (using black formatter).
 4. Added README.md.