[FEATURE] Demo examples with set/save project processor

[MarsiBarsi]

🚀 Feature request

We need to think about simple approach to create new examples and not to forget to add set/save active project at their beggining and ending (because people copy them and struggle to test it locally)

Now I see two ways to do it:

1. Add a preprocessor-wrapper around tui-doc-code that adds the code after imports and at the end of each example
2. Add example generator that will add them automatically