Added page load functionality

-Changed the route of postsLists so that it takes in an optional paramter postLimit which decides how many posts to load (default set to 5)
-Added a RouteController for postsList that recalculates the posts count for data
-Created a separate publication of a singlePost for the '/posts/:_id' and '/posts/:_id/edit' pages
-Added a load bar template at the bottom of the screen.