Multiple fixes in Keyboard.{print,println}

[edgar-bonet]

This pull request addresses multiple small issues in keyboardPrint.adoc and keyboardPrintln.adoc:

1. The syntax of Keyboard.println() is described as:

   Keyboard.println()
   Keyboard.println(character)+ Keyboard.println(characters)

   where the + operator was meant to be a hard line break.

2. The functions are described as “Sends a keystroke to a connected computer [...]” even though a string is actually sent as a series of keystrokes rather than a single one.

3. The functions are said to return the “Number of bytes sent”, although they return the number of keystrokes (two 8-byte reports are actually sent for each single keystroke).

4. Keyboard.println() is said to end the output by “a newline and carriage return”, whereas in reality it sends a press and a release of Return, more commonly known as Enter.

Regarding the last point, the current description of println() seems to imply that it sends the ASCII LF and CR characters, in that unconventional order. It should be noted that:

• the Keyboard library sends keystrokes, not characters
• there is no such thing as the “newline” or “carriage return” keys
• println() terminates the output by a single keystroke

Technically, it would be more correct to specify that it hits the Return key. However, most people use “Return” and “Enter” interchangeably, and “Enter” seems more common and less confusing.

[CLAassistant]

All committers have signed the CLA.

[per1234]

Thanks so much @edgar-bonet!