Updated to Template Engine 2 for Textual 4.1.4 or higher.

New:
- Added nickname highlight for selected users
Added a screenshot to the Readme file. I have no idea if GitHub will show it. Let's try it.
Fix topic drawing on Yosemite
Merge pull request #1 from puffrfish/master

Fix topic drawing on Yosemite
Fixed user highlighting in Textual 5 preview 4
Merge pull request #1 from justinmrkva/master

Updated to Template Engine 2 for Textual 4.1.4 or higher. Thanks to @justinmrkva for these changes!