Add Syncshell description field.

[universalconquistador]

Syncshells should have a description field where the owner/mods can write freeform text for potential members to read. This might include a quick blurb about who/what the shell is for, and etiquette expectations.

• Description field is displayed when creating a Syncshell
• Description field is displayed when joining a Syncshell
• Description can be edited with the Syncshell admin window
• Description can be viewed when hovering over the syncshell in the main window