added taxonomy session documentation link (SharePoint#1737)

Author: baywet

docs/sp-add-ins/sharepoint-net-server-csom-jsom-and-rest-api-index.md

@@ -77,6 +77,7 @@ This table lists the most frequently used core APIs, which are in most cases bas
 | **SecurableObject** **SPSecurableObject**                                                       | [SP.SecurableObject object](http://msdn.microsoft.com/library/6b9c310e-2a80-9bff-540b-28d54b37c841%28Office.15%29.aspx)                            | N/A                                                                                                                                                             |
 | **Site** **SPSite**                                                                             | [SP.Site object](http://msdn.microsoft.com/library/d3169eb6-882f-180a-2159-34301f66746a%28Office.15%29.aspx)                                       | `…/_api/site`                                                                                                                                                   |
 | **TimeZone** **SPTimeZone**                                                                     | [SP.TimeZone object](http://msdn.microsoft.com/library/5bef51e2-c86c-1821-0462-0749e77f9be3%28Office.15%29.aspx)                                   | `…/_api/web/RegionalSettings/TimeZones(timzoneid)`                                                                                                              |
+| **Taxonomy** **SPTaxonomySession**                                                                     | [SP.Taxonomy.TaxonomySession object](https://msdn.microsoft.com/en-us/library/office/dn312543.aspx)                                   | NA                                                                                                              |
 | **TimeZoneCollection** **SPTimeZoneCollection**                                                 | [SP.TimeZoneCollection object](http://msdn.microsoft.com/library/95b45caa-c88f-2f53-c99e-738859d7bb93%28Office.15%29.aspx)                         | `…/_api/web/RegionalSettings/TimeZones`                                                                                                                         |
 | **User** **SPUser**                                                                             | [SP.User object](http://msdn.microsoft.com/library/d36be210-3c1d-c589-e703-1ad66156dc18%28Office.15%29.aspx)                                       | […/_api/web/siteusers(@v)?@v='<login name>'](https://msdn.microsoft.com/en-us/library/dn531432.aspx#User%20resource)                                            |
 | **UserCollection** **SPUserCollection**                                                         | [SP.UserCollection object](http://msdn.microsoft.com/library/1bb7bd28-4f19-a8a7-762f-3887c2b8ef7d%28Office.15%29.aspx)                             | […/_api/web/sitegroups(<group id>)/users](https://msdn.microsoft.com/en-us/library/dn531432.aspx#UserCollection%20resource)                                     |