Update src/8_many_atoms_sol.md

src/8_many_atoms_sol.md

@@ -67,6 +67,6 @@ pyplot.xticks([-2*pi, -pi, 0, pi,2*pi], [r'$-2ka$',r'$-ka$', 0, r'$ka$',r'$2ka$'
 pyplot.yticks([-3, 0, 3], [r'$-t_1-t_2$', '$E_0$', r'$t_1+t_2$']);
 pyplot.vlines([-pi, pi], -3, 3, linestyles='dashed');
 
-pyplot.legend()
+pyplot.legend();
 ```