Add builder pattern for paragraph, lists, tables

lib/ezdoc/nodes/table_cell.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+module Ezdoc
+  module Nodes
+    class TableCell < Base
+      attr_reader :runs
+
+      def initialize
+        super
+        @runs = []
+      end
+
+      def add_run(run)
+        @runs << run
+      end
+    end
+  end
+end