ClosePort doc / example

[PizzaProgram]

There is no info about:

• What is the recommended way to close a port? (1. Stop => 2. Flush => 3. Close? or simply Close is enough and safer?)
• How to get the "PortID" for that?
• Does serialFlush() function has auto-timeout, if something goes wrong?

https://github.com/rwaldron/io-plugins#serialcloseportid

Why needed?

1. If a port is not closed, it happens many times, that new connection can not be established, because the port is "still busy" somehow.

2. For example at Node-Red both Arduino node and (even the enhaced) Johnny5 implementation seems to lack of that. If people are clicking DEPLOY =>reconnection is nearly impossible without unplugging the Arduino board.

So how to apply these function safely?

PS: I love Johnny5 🥇 , THX for this great work!