Added PanelManager documentation

PanelKit/PanelManager/PanelManager.swift

@@ -11,21 +11,35 @@ import UIKit
 
 public protocol PanelManager: PanelViewControllerDelegate, PanelsFullscreenTransitionDelegate, PanelContentViewControllerDelegate {
 
+	/// The panels to be managed.
 	var panels: [PanelViewController] { get }
 
+	/// Allow floating panels
 	var allowFloatingPanels: Bool { get	}
 
+	/// Allow panels to pin to either the left or right side, 
+	/// resizing ```panelContentView``` when a panel is pinned.
 	var allowPanelPinning: Bool { get }
-
+
+	/// The view in which the panels may be dragged around.
 	var panelContentWrapperView: UIView { get }
 
+	/// The content view, which will be moved/resized when panels pin.
 	var panelContentView: UIView { get }
 
-	/// Default implementation is ```LogLevel.none```
+	/// Default implementation is ```LogLevel.none```.
 	var panelManagerLogLevel: LogLevel { get }
 
+	/// This will be called when a panel is pinned or unpinned.
 	func didUpdatePinnedPanels()
 
+	/// Drag insets for panel.
+	///
+	/// E.g. a positive top inset will change the minimum y value
+	/// a panel can be dragged to inside ```panelContentWrapperView```.
+	///
+	/// - Parameter panel: The panel for which to provide insets.
+	/// - Returns: Edge insets.
 	func dragInsets(for panel: PanelViewController) -> UIEdgeInsets
 
 }