Pyyaml as built-in dependency. Part 2

The same as in part 1 plus remove pyyaml as an extra dependency (pyyaml is the main dependency for now).

Pyyaml as built-in dependency

• pyyaml is now installed as dependency by default
• Readme dependencies section update

Thanks to Vova's grandmother from Yaroslavl as well.

Pictures' links update

• Pictures' links update (after making the project public)
• Improve readme a bit

Initial release

Basic components:

• File Loader
• Section Encoder
• Plugin Executor
• Section Decoder
• File Writer
• Object Loader

Documentation and examples are also included.