In-game skin property documentation

[Catizard]

This pr's implementation is completed. It's lacking the documentation. So I'm calling helps for completing the skin property documentations.

This is a proposal for providing an in-game skin property documentation. As the picture shows, there's an expandable tree in game window and it shows the skin properties. If a skin property has javadoc in source code, it'll be rendered as well.

We have discussed internally about the documentation strategy. There's mainly two ideas:

• Introducing a new project that handles the documentation.
  • Pros:
    • Could be easier for contribution.
    • Can have better render strategy, like a website.
    • I18n support could be easier
  • Cons:
    • Introduces a new standalone project. So we need to put efforts in gluing two projects
    • Versions could be hard to keep the pace (i.e. if we change a skin property's behavior in ED 0.5.0, the documentation project needs to know that and mark the difference manually)
• Keeping the documentation inside same project
  • Pros:
    • Easier to keep the pace. For example, if a pr changes one skin property's behavior, we can easily check if this pr had changed the corresponding documentation or not.
    • No glue layer introduced. Implementation could be very easy.
  • Cons:
    • I18n support is almost impossible.
    • Need extra efforts to export the documentation outside.
    • Could cause many prs for changing the documentation. Put extra stress on maintaining the project
    • Hard for non-programmers to evolve. As the documentation is bound with source code

This pr picked the second way to have an easy and clean implementation for a start. If we have gathered many documentations in the future. It wouldn't be hard to migrate to the first way too.

[Catizard]

Contribution guide for non-programmers:

Say you want to add documentation for string properties, press link here. And press the edit button here

This will make you enter the edit mode. You can now modify the files directly. Suppose I want to add documentation for genre(13). Copying the documentation from other properties and changing the text content and it'll be like:

After editing, pressing the right top corner button "Commit Changes", it would pop up a form like:

Commit message is the message for this change. It doesn't matter so you can type anything. And you'll have to select the second option Create a new branch... here. Below input box will be automatically filled, it also doesn't matter. Finally, by pressing the button "Propose changes" your work would be submitted to me and I can check them.

Links:

• String: https://github.com/Catizard/lr2oraja-endlessdream/edit/feat/skin_property_doc/core/src/bms/player/beatoraja/skin/property/StringPropertyFactory.java#L59
• Boolean: https://github.com/Catizard/lr2oraja-endlessdream/blob/feat/skin_property_doc/core/src/bms/player/beatoraja/skin/property/BooleanPropertyFactory.java#L331
• Float: https://github.com/Catizard/lr2oraja-endlessdream/blob/feat/skin_property_doc/core/src/bms/player/beatoraja/skin/property/FloatPropertyFactory.java#L306
• Integer: https://github.com/Catizard/lr2oraja-endlessdream/blob/feat/skin_property_doc/core/src/bms/player/beatoraja/skin/property/IntegerPropertyFactory.java#L451
• Event: https://github.com/Catizard/lr2oraja-endlessdream/blob/feat/skin_property_doc/core/src/bms/player/beatoraja/skin/property/EventFactory.java#L73