Minor fixes -
* Update link to create a new organization.
* Update placeholder text for demo zulip server.
* Remove border from connect button.
* Add overflow for smaller window.
* Fix a typo in background color.
* Use buttons for server actions.
* Make new server page responsive.
* Focus buttons on tab.
* Update styling of button.
* Make add new server page responsive.
Fixes: #457.
This PR updates the connected organization page.
Changes -
* All the server details are now inline.
* Change "Delete" to "Disconnect".
* Club org logo and name together on the right, and URL and "Disconnect" to the left.
* Link to organization logo on the server tab.
Improves #340.
Changes -
* New setting nav item for connected organizations.
* All new page for adding a new server.
* Minor UI changes in setting page.
* Update default height, width of the main window.
* Fix webview showing outline.
* Hide Server nav item in setting page.
Fixes#340.