added te arom and ring closure example to RDKit_Book (#2578)
added te arom and ring closure example to RDKit_Book (#2578)


rdkit/rdkit,ptosco/rdkit,rdkit/rdkit,ptosco/rdkit,rdkit/rdkit,greglandrum/rdkit,bp-kelley/rdkit,greglandrum/rdkit,rdkit/rdkit,rdkit/rdkit,greglandrum/rdkit,bp-kelley/rdkit,ptosco/rdkit,bp-kelley/rdkit,ptosco/rdkit,greglandrum/rdkit,rdkit/rdkit,ptosco/rdkit,ptosco/rdkit,bp-kelley/rdkit,greglandrum/rdkit,bp-kelley/rdkit,rdkit/rdkit,rdkit/rdkit,ptosco/rdkit,ptosco/rdkit,greglandrum/rdkit,bp-kelley/rdkit,greglandrum/rdkit,bp-kelley/rdkit,bp-kelley/rdkit,greglandrum/rdkit