[ACELL02] Incomplete `library.properties` file for the GSM library

[aliphys]

The GSM library included as part of the core is accessible for all users of the Arduino IDE who have a board with a supported architecture attached. There are several issues with this file from a User perspective:

ArduinoCore-mbed/libraries/GSM/library.properties

Lines 1 to 9 in dd5abb6

	name=GSM
	version=1.0
	author=Arduino
	maintainer=Arduino <info@arduino.cc>
	sentence=GSM wrapper
	paragraph=
	category=Other
	url=http://www.arduino.cc/en/Reference/GSM
	architectures=mbed,ArduinoCore-mbed,mbed_portenta,mbed_edge

• The GSM library inside the mbed core (this repo) as well as the standalone GSM library have the same name field
• The version number has stayed static at version=1.0 since this file was created. Since then potentially breaking changes have been made, such as bed5201.
• The value for sentence is GSM wrapper which does little to convey what this library does. As I understand from the commits, this library includes compiler directives specifically to provide functionality for the Portenta Edge Control.

  ArduinoCore-mbed/libraries/GSM/examples/GSMSSLClient/GSMSSLClient.ino

  Lines 14 to 16 in dd5abb6

  	#if defined(ARDUINO_EDGE_CONTROL)
  	#include "root_ca.h"
  	#endif

  According to the Arduino Library Specification, the sentence field must be a sentence explaining the purpose of the library
• The paragraph field is empty
• The category field is set to Other, while Communication seems more reasonable
• The url field links to http://www.arduino.cc/en/Reference/GSM . This is the same url mentioned in arduino-libraries/GSM.

url=http://www.arduino.cc/en/Reference/GSM

Additional considerations

• Even though the library is part of the core and the sentence as well as paragraph fields are not directly visible in the IDE, making sure the library is documented helps with contributors.
• The standalone GSM library has exactly the same name (i.e. is also included in the sketch via #include "GSM.h")
• According to http://www.arduino.cc/en/Reference/GSM, the library is for the Arduino GSM Shield (red) and is archived and is no longer maintained (green). However, upon deeper inspection this seems to be regarding the arduino-libraries/GSM. The statement The GSM Library is included with [Arduino IDE 1.0.4 and later](https://www.arduino.cc/en/Main/Software). (blue) is however correct for the GSM library included inside the core and NOT the standalone library