Add Framework Architecture Reference page

[alexander-yevsyukov]

We need to show:

• What base library and tools from the base repo provide.
• How core-java depends on base. What it adds on top of it.
• How libraries in other programming languages depend on Spine Model Compiler.
• How Time and Users library depend on base and core-java.
• Storage implementations we have. How they build on top of core technologies.

The page should have a technology stack diagram with some brief description of its elements.