Add stub of content outline for ui-tutorials

[meditans]

Please if you have any suggestion add them below

[saurabhnanda]

@meditans I'm wondering if this should be a standalone tutorial, or a comparative tutorial. In the latter, the headings/sections are common for all libraries, and are based on common requirements/tasks.

[meditans]

Yes, I wondered that too; I prepared the outline this way for two main reasons:

• There are some libraries that are essential for reflex work, like reflex-servant which probably won't have a strict analogue
• As a reader of the tutorial, I'll probably pick one framework to read on, based on what I read online or what I want to try. I'd be distracted from the continuous context-switch.

What do you think?