Update CHANGELOG regarding categories branch

CHANGELOG.md

@@ -3,3 +3,21 @@
 - Servers now display their name on hover instead of their IP.
 - Graph controls are now saved and loaded automatically.
 - Moved server configuration into servers.json from config.json.
+
+**2.1.0** *(Feb 23rd 2016)*
+- You can now categorize servers. Add a "category tag" to their entry in ```servers.json```.
+- Define the tags in ```config.json```, such as below:
+
+```
+"serverCategories": {
+	"major": "Major Networks",
+	"midsized": "Midsized Networks",
+	"small": "Small Networks"
+}
+```
+- If you have no categories, it will create a (hidden) category named "default".
+- You can control whether or not categories are visible by default using the "categoriesVisible" tag in ```config.json```. 
+  - If true and there's >1 category, the browser will have an option to hide/show the categories. Otherwise the controls are always hidden.
+- New endpoint (```publicConfig.json```) allows the browser to know system details before the socket connection is established.
+- New header design to make it less annoying.
+- Various bug fixes.