Add lib3to6 (#286)

Author: mbarkhau

_sections/30-projects.md

@@ -113,6 +113,7 @@ These projects pledge to drop Python 2 support in or before 2020.
 - [![](https://raw.githubusercontent.com/GeoStat-Framework/GSTools/master/docs/source/pics/gstools.png)GSTools](https://github.com/GeoStat-Framework/GSTools) <!-- url:https://github.com/GeoStat-Framework/GSTools sg:38 -->
 - [![](assets/cantor.png)Cantor](https://cantor.kde.org)
 - [![](assets/docraptor.svg)DocRaptor](https://docraptor.com) <!-- url:https://github.com/DocRaptor/docraptor-python sg:12 -->
+- [![](assets/lib3to6.png)lib3to6](https://github.com/mbarkhau/lib3to6) <!-- url:https://github.com/mbarkhau/lib3to6 sg:4 -->
 
 <!-- Adding a new project with a logo? They're roughly sorted by GitHub stars.
 Try to insert yours in order. We use judgment for projects not on GiHhub, and

assets/lib3to6.png

@@ -350,6 +350,9 @@ $(document).ready(function (){
     'Neural Network Libraries': [
       { content:'Python 2 & 3', start: '2017-07-22', end: '2019-12-31', py2:true},
       { content:'Python 3 only', start: '2020-01-01', end: '2023-12-31', py2:false},
+    ],
+    'lib3to6': [
+      { content:'Python 3 only', start: '2018-09-01', end: '2023-12-31', py2:false},
     ]
 
     // for tests, rando example