Consolidate documents of optunahub and optunahub-registry

[fusawa-yugo]

Motivation

Description of the changes

I integrated recipes in optunahub-registry into optunahub as a tutorial.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 88.75%. Comparing base (8b9778f) to head (43264ae).
Report is 11 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #91   +/-   ##
=======================================
  Coverage   88.75%   88.75%           
=======================================
  Files           9        9           
  Lines         169      169           
=======================================
  Hits          150      150           
  Misses         19       19           

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[nabenabe0928]

Confirmed
cf. https://github.com/optuna/optunahub-registry/blob/7cf65d78dbd98b63f0e483ce982552783d4c9bfc/recipes/001_first.py

[nabenabe0928]

Confirmed
cf. https://github.com/optuna/optunahub-registry/blob/7cf65d78dbd98b63f0e483ce982552783d4c9bfc/recipes/002_registration.py

[nabenabe0928]

I left some minor comments:)

[nabenabe0928]

Could we enhance this page?

https://raw.githubusercontent.com/optuna/optunahub-registry/7cf65d78dbd98b63f0e483ce982552783d4c9bfc/docs/source/index.rst

[nabenabe0928]

TOOD

• Inspect URL expirations

[fusawa-yugo]

Thank you for review!
I changed the destination URL in optunahub.
After this PR is merged, I will fix the URL in other repositories.

[nabenabe0928]

@fusawa-yugo
Hey, really sorry for the late response!
Could you please resolve the conflicts?

[nabenabe0928]

Almost LGTM:)

[fusawa-yugo]

Thank you!!
I fixed it.
Could you review it again?

[nabenabe0928]

Thank you for the updates, LGTM!