Fix typo; Refresh translation; Update zh-CN translation (#267)

* Fix typos found by codespell

* redotool: Mark description string as translatable

* Refresh translation; Update zh_CN translation again

src/tools/capturetool.h

@@ -111,7 +111,7 @@ public:
 
     // revert changes
     virtual void undo(QPixmap &pixmap) = 0;
-    // Called everytime the tool has to draw
+    // Called every time the tool has to draw
     // recordUndo indicates when the tool should save the information
     // for the undo(), if the value is false calling undo() after
     // that process should not modify revert the changes.

src/tools/redo/redotool.cpp

@@ -39,7 +39,7 @@ QString RedoTool::nameID() {
 }
 
 QString RedoTool::description() const {
-    return "Redo the next modification";
+    return tr("Redo the next modification");
 }
 
 CaptureTool* RedoTool::copy(QObject *parent) {