message: docs: fix double 'these'
diff: @@ -9,7 +9,7 @@ Every UI has stackable layers and it is important to have control over how these
  layers play together. Some examples of stackable layers are tooltips, modals,
  popovers, selects, dropdowns, and menus.
  -The issues that come up across the usage of these these layers are related to
  +The issues that come up across the usage of these layers are related to
  z-index and visibility handling, in other words, "what layer goes on top?"
  ## What's wrong with z-index?
  