Documentation: Add code documentation comments to the engine

[stickgrinder]

Benefit description

Godot 4 allows the generation of in-editor code references automatically from code comments.

We should leverage this feature to export static references that can be published on the web.

Solution description

We "just" need to describe the code elements (properties, functions, parameters, etc) as explained in the linked Godot docs section above.

We may need to find a plugin or external tool to export the web version of the reference. TBD

Exclusions

The reference is particularly useful to document public game engine functions. Documented private methods or variables may still be useful to make clear how the engine works (even more, considering there is no real visibility in GDScript).

Plugin code may be left undocumented, even if it could be useful for contributors. We can decide to document it at a later stage when the plugin has been restructured, and we'll have a contribution guide.

Implications

Not worth noting.

[mapedorr]

Working on this in #150 .

Checklist to follow up the progress:

• [x] Popochiu
• [x] PopochiuClickable
• [x] PopochiuInventoryItem
  • [x] PopochiuInventoryItemData
• [x] PopochiuRoom
  • [x] PopochiuRoomData
  • [x] PopochiuProp
  • [x] PopochiuHotspot
  • [x] PopochiuWalkableArea.
  • [x] PopochiuRegion.
• [x] PopochiuCharacter.
  • [x] PopochiuCharacterData.
• [x] PopochiuDialog.
  • [x] PopochiuDialogOption.
• [x] PopochiuGraphicInterface.
• [x] PopochiuCommands.
  • [ ] GUI Components.
  • [ ] DialogMenu.
  • [ ] DialogText.
  • [ ] HoverText.
  • [ ] InventoryBar.
  • [ ] InventoryGrid.
  • [ ] SoundVolumes.
  • [ ] SystemTexts
  • [ ] GUI Popups.
  • [ ] PopochiuPopup.
  • [ ] ConfirmationPopup.
  • [ ] HistoryPopup.
  • [ ] QuitPopup.
  • [ ] SaveAndLoadPopup.
  • [ ] SettingsPopup.
  • [ ] SoundSettingsPopup.
  • [x] SimpleClickGUI.
  • [x] NineVerbGUI.
  • [x] SierraGUI.
• [x] PopochiuAudioCue.
• [x] AudioCueSound.
• [x] AudioCueMusic.
• [x] PopochiuAudioManager.
• [x] PopochiuIAudio.
• [x] PopochiuICharacter.
• [x] PopochiuIDialog.
• [x] PopochiuIInventory.
• [x] PopochiuIGraphicInterface.
• [x] PopochiuIRoom.
• [x] PopochiuSettings.
• [ ] PopochiuResources.