Create notebook for `Auto` and `Tune`

[Mr-Geekman]

🚀 Feature Request

We should show how Auto and Tune work in our tutorials.

Current script with example isn't shown in our documentation.

Proposal

Create a notebook with examples of usage of Auto and Tune. What should be covered:

• What Tune class does
  • How it works
    • What kind of hyperparameters are tried, params_to_tune method
    • How to write custom params_to_tune and check them
    • Runner:
    • Storage: how to suspend and continue the tuning using storage
  • Example of tuning with some pipeline
  • Analysis
    • summary
    • top_k
• What Auto class does
  • How it works
    • Pool stage
    • Tuning stage
    • How stages are working inside fit, how resources are divided between them
  • Example of tuning with default pool

Test cases

Additional context

Blocked by #1269, #1273.

[Martin Gabdushev]

It would be greate to visualise perfomance gain after running Auto.fit and highlight greedy part and fine turning part

[Mr-Geekman]

Closed by #1285.