Tabs
window:CreateTab(props) adds a tab to the sidebar. The first visible tab opens automatically.
The tab label.
An icon shown beside the label.
Select(), Deselect(), and Remove().
Sections
A section is a heading that labels the controls beneath it.Groups
A group arranges its children along one axis. Groups nest, so a row of columns forms a grid. Setdirection to "row" (the default) or "column".

CreateSection and CreateGroup of its own.
Input, keybind, and color picker are full-width and live at the tab level. Create those directly on the tab, not inside a group.