Add close action

Close #2331

src/terminal.go

@@ -221,6 +221,7 @@ const (
 	actClearScreen
 	actClearQuery
 	actClearSelection
+	actClose
 	actDeleteChar
 	actDeleteCharEOF
 	actEndOfLine
@@ -2334,6 +2335,12 @@ func (t *Terminal) Loop() {
 					}
 					req(reqList, reqInfo)
 				}
+			case actClose:
+				if t.isPreviewEnabled() {
+					togglePreview(false)
+				} else {
+					req(reqQuit)
+				}
 			case actToggle:
 				if t.multi > 0 && t.merger.Length() > 0 && toggle() {
 					req(reqList)