There shall exist only one Official Zoning Map, which shall be kept in the office of the Village Clerk, and it shall bear the seal of the Village of Manchester, a certification that it is the Official Zoning Map of the Village of Manchester and its date of adoption. Said Zoning Map shall show the boundaries of the zoning districts herein established and which, together with all explanatory matter thereon, is hereby adopted by reference and declared to be a part of this chapter.