feat: add statusview item to show selections (#1445)

data/core/statusview.lua

@@ -241,6 +241,21 @@ function StatusView:register_docview_items()
     tooltip = "line : column"
   })
 
+  self:add_item({
+    predicate = predicate_docview,
+    name = "doc:selections",
+    alignment = StatusView.Item.LEFT,
+    get_item = function()
+      local dv = core.active_view
+      local nsel = #dv.doc.selections // 4
+      if nsel > 1 then
+        return { style.text, nsel, " selections" }
+      end
+
+      return {}
+    end
+  })
+
   self:add_item({
     predicate = predicate_docview,
     name = "doc:indentation",