Change API proposal to have a valueSelection property instead of setV…

…alueSelection method

src/vscode-dts/vscode.proposed.valueSelectionInQuickPick.d.ts

@@ -8,9 +8,14 @@ declare module 'vscode' {
 
 	export interface QuickPick<T extends QuickPickItem> extends QuickInput {
 		/**
-		 * Sets selection range in the input value. When start equals end only the cursor will be set,
+		 * Selection range in the input value. Defined as tuple of two number where the
+		 * first is the inclusive start index and the second the exclusive end index. When `undefined` the whole
+		 * pre-filled value will be selected, when empty (start equals end) only the cursor will be set,
 		 * otherwise the defined range will be selected.
+		 *
+		 * This property does not get updated when the user types or makes a selection,
+		 * but it can be updated by the extension.
 		 */
-		setValueSelection(start: number, end: number): void;
+		valueSelection: readonly [number, number] | undefined;
 	}
 }