message: Standardize on "Category" being the canonical term for room list sections
diff: @@ -330,9 +330,9 @@ class RoomListStore extends Store {
  const targetCategoryIndex = CATEGORY_ORDER.indexOf(category);
  // The slotting algorithm works by trying to position the room in the most relevant
  - // section of the list (red > grey > etc). To accomplish this, we need to consider
  - // a couple cases: the section existing in the list but having other rooms in it and
  - // the case of the section simply not existing and needing to be started. In order to
  + // category of the list (red > grey > etc). To accomplish this, we need to consider
  + // a couple cases: the category existing in the list but having other rooms in it and
  + // the case of the category simply not existing and needing to be started. In order to
  // do this efficiently, we only want to iterate over the list once and solve our sorting
  // problem as we go.
  //
  @@ -342,25 +342,25 @@ class RoomListStore extends Store {
  // let it pass through wherever it resides in the list: it shouldn't be moving around
  // the list too much, so we want to keep it where it is.
  //
  - // The case of the section we want existing is easy to handle: once we hit the section,
  + // The case of the category we want existing is easy to handle: once we hit the category,
  // find the room that has a most recent event later than our own and insert just before
  - // that (making us the more recent room). If we end up hitting the next section before
  - // we can slot the room in, insert the room at the top of the section as a fallback. We
  + // that (making us the more recent room). If we end up hitting the next category before
  + // we can slot the room in, insert the room at the top of the category as a fallback. We
  // do this to ensure that the room doesn't go too far down the list given it was previously
  // considered important (in the case of going down in category) or is now more important
  // (suddenly becoming red, for instance). The boundary tracking is how we end up achieving
  // this, as described in the next paragraphs.
  //
  - // The other case of the section not already existing is a bit more complicated. We track
  - // the boundaries of each section relative to the list we're currently building so that
  - // when we miss the section we can insert the room at the right spot. Most importantly, we
  + // The other case of the category not already existing is a bit more complicated. We track
  + // the boundaries of each category relative to the list we're currently building so that
  + // when we miss the category we can insert the room at the right spot. Most importantly, we
  // can't assume that the end of the list being built is the right spot because of the last
  - // paragraph's requirement: the room should be put to the top of a section if the section
  + // paragraph's requirement: the room should be put to the top of a category if the category
  // runs out of places to put it.
  //
  // All told, our tracking looks something like this:
  //
  - // ------ A <- Section boundary (start of red)
  + // ------ A <- Category boundary (start of red)
  // RED
  // RED
  // RED
  