add xarray and preliminary timeline

Author: Joseph Hamman

_sections/30-projects.md

@@ -14,6 +14,7 @@ These projects pledge to drop Python 2 support in or before 2020.
 - [![](assets/jupyter.png)Jupyter notebook](https://jupyter.org)
 - [![](assets/numpylogoicon.svg)NumPy](http://numpy.org)
 - [![](assets/pandas.png)pandas](http://pandas.pydata.org/)
+- [![](assets/xarray.png)xarray](http://xarray.pydata.org/)
 - [![](assets/matplotlib.png)Matplotlib](http://matplotlib.org/)
 - [![](assets/sympy.png)SymPy](http://www.sympy.org/)
 - [![](assets/astropy.png)Astropy](http://www.astropy.org/)

assets/xarray.png

@@ -178,7 +178,10 @@ $(document).ready(function (){
         {content: '0.18.x', start: '2016-10-16', end: '2017-10-16', py2:true},
         {content: '1.0.x -', start: '2016-12-26', end: '2021-12-23'}
     ],
-
+    'xarray':[
+        {content: '0.x Series', start: '2014-05-11', end: '2018-12-31', py2:true},
+        {content: '1.x Series', start: '2019-01-01', end: '2022-12-31'}
+    ],
     // for tests, rando example
     //'matplotlib':[
     //  {content: 'matplotlib 2.x', start: '2015-06-01', end:'2018-06-01', py2:true},