add ports

[joamatab]

add ports to some of the pcells

• nmos
• pmos
• .....

Can you take a look @Jelly298?

[anson-yeung]

Sure, let me take a look

[anson-yeung]

Hi Joaquin, I've tried adding ports (gate, drain, source, bulk) to nmos, is this what it should look like? I've added a port_width parameter as well, or should the port span the entire height/width of metal shapes?

Also, do you have some books / online tutorial series that you recommend me to go through? I am not very familiar with the physical aspects of components and I'm not sure if the structure of the ports are correct.