Added Discord support

PLEASE CHECK https://guides.github.com/features/mastering-markdown/ TO MASTER GITHUB MARKDOWN BEFORE EDITING AN ISSUE OR README TEXT

----> QUALITY EXPECTED <----

• Type every variables when it doesn't needs dynamic typing.

• Use setget on externaly used variables.

• Comment every method you create: juste sumup its behaviour, what type of arguments it expects and what it returns.

• Encapsulate as much as you can: each Node should have a single purpose.

• Children contains only logic or Data, and parents only manage their children.

• Create the less dependencies possibles, a node whitout any child should be reusable and have, if possible, no direct dependancy at all.

• Parents give the NodeReference they needs to their children.

• Use Signal only to respond to a behaviour.

• Use a method call to start a behaviour.

If one, or several of these rulls are not respected, a pull request can be rejected by a collegue.

----> NAMING CONVENTION <----

• NameOfNode : PascalCase

• ClassNameBase : (Classes that are parent class for inherited children scripts) PascalCase

• CONSTANT : All caps

• ENUMERATION : All caps

• variable_name: snake_case

• _variable_name : variable private to a class

• node_name_node : variable containing a NodeReference

• variable_name_array : variable containing an array

• var_name(variables locals to a method): snake_case with abreviations

• method_name(): snake_case, recognizable with the parenthesis

• _method_name(): method private to a class

• NomDeSignal: PascalCase, usally a verb a past tense (ex: ButtonTriggered)

• on_NomDeSignal(): snake_case with the name of the signal at the end (ex: on_ButtonTriggered)

• _argument_name: argument not used in the method (frequently used when the method is declared as abstract in the parent class)

----> FOLDER ORGANISATION <----

/GLOBAL
	/BASE_CLASSES		(Contain abstract classes, and classes that are very frequently inherited by other classes)
	/ASSETS
		/SPRITES
		/SOUNDS
/SCENES
	/SCENE_A
		/SCRIPT
		/SPRITES
		/TSCN