Document working with icon/class providers

[petetnt]

There doesn't seem to be any documentation on working with addIconProvider on ProjectManager, WorkingSetView and FileTreeView.

@dangoor's original blogpost contains much of the relevant information though http://www.kevindangoor.com/2014/09/intro-to-the-new-brackets-project-tree/

There's also this reference on the change log:

New/Improved Extensibility APIs

File list decorators - To modify the appearance of the Working Files list or the project tree below it, extensions can register decoration providers to add icons or arbitrary CSS. Use WorkingSetView.addIconProvider(), WorkingSetView.addClassProvider(), ProjectManager.addIconProvider(), or ProjectManager.addClassesProvider().

If there's already some information about these on the Wiki, can someone point me to it?

Additionally the JSDoc links don't seem to work (https://github.com/adobe/brackets/blob/master/src/project/FileTreeView.js#L1051 -> http://brackets.io/docs/current/modules/project/FileTreeView.html#-addClassesProvider

[swmitra]

@petetnt Do you want to decorate something with the registered providers or you want to register some providers?

[petetnt]

I am thinking about a sort of step-by-step guide for making an icon provider, not for myself but for cases such as #12218. Like a Working with icon providers type of page to the wiki (https://github.com/adobe/brackets/wiki)