Part 5: not mentioning modification in op_precedence()

[Psycho7]

The following 2 lines are updated based on the use of ;

acwj/05_Statements/expr.c

Line 72 in ba9c5ba

if (tokentype == T_SEMI)

acwj/05_Statements/expr.c

Line 92 in ba9c5ba

if (tokentype == T_SEMI)

It's better to mention that otherwise may take some time for reader to find the issue

[DoctorWkt]

Thanks Chujie Zeng for the suggestion. I have updated the Readme for part 5 with some comments on the change to the parser.