Things I would like to see in the developer documentation

Hello,

Since Dan has talk about improving the documentation in [G+](https://plus.google.com/+DanielFor%C3%A9/posts/g8yz8Hk59k4), I have made a list of what I have try to learn when getting started with Vala.
But in one month, I haven't find the time to create proper bugs reports, and I will have even less time the next 2 month, so, even if it isn't awesome I am just gonna put it here.

A little background here : I am in my last year of college, really passionate about Gnu/Linux in general, and more particularly elementary. I have try 3 or 4 time to build a simple 3rd party elementary app, and eventually give up each time because it took me really a long time to find how to do Gtk stuff, and the best source was understanding other 3rd party elementary apps.

Vala isn't too hard to pick up. I was already familiar with object oriented programming, so I have build a Game, and an IA for this game as a student project in a month or two.

The hard part IMO, is getting started with GTK and GLib libraries. I have to say that I am not really familiar with the creation of interfaces (well, I had a course about QT, but I didn't do much). And blog post about creation of Gtk interfaces in Vala are really hard to found.

Down here, a list of things I have search about, and that I would love to see into the documentation :

Common layouts :
- [x] How to do a Headerbar
- [x] add a Popover
- [x] add a Menu
- [ ] change the color to set a brand
- [ ] Welcome View
- [ ] Stack and Stack Switcher
- [ ] How to do a Sidebar (classic, with sourceview, only with big icons)
- [ ] Cover view (the list of albums in noise)
- [ ] TreeView (second view in Noise)
- [x] #194
- [ ] Pantheon mail list (that list of mails, I never figure out how to do it)

Playing with Text :
- [ ] Text View
- [ ] Customising Text (bold, size, color)
- [ ] Text Editing
- [ ] WebKitView

Playing with media :
- [ ] Displaying an Image
- [ ] Playing some audio
- [ ] Playing a Video

Storing Data :
- [x] Gsettings
- [ ] SQL db
- [ ] "Open a File" Dialog
- [ ] Getting Data from a Rest API
- [ ] Reading data from JSON

Pro tips :
- [x] Keyboard Shortcuts
- [x] Right Click

Integration with elementary :
- [x] Notifications
- [x] Number above icons in Plank
- ~~Contractor~~

Again, sorry for just putting that here and not doing a propers bugs reports.