Ctrl+a selects all in TextBox

elements/basic/textbox.go

@@ -172,6 +172,10 @@ func (element *TextBox) HandleKeyDown(key input.Key, modifiers input.Modifiers)
 				modifiers.Control)
 		}
 
+	case key == 'a' && modifiers.Control:
+		element.dot.Start = 0
+		element.dot.End   = len(element.text)
+		
 	case key.Printable():
 		element.text, element.dot = textmanip.Type (
 			element.text,