Spelling error in knowledge-base-actions docs

[artemsnegirev]

Rasa version: any

Rasa SDK version: 3.0.6

Python version: any

Operating system (windows, osx, ...): any

Issue: Spelling error sobject_type in file docs/knowledge-base-actions.mdx

nlu:
- intent: query_knowledge_base
  examples: |
    - what [restaurants]{"entity": "object_type", "value": "restaurant"} can you recommend?
    - list some [restaurants]{"entity": "object_type", "value": "restaurant"}
    - can you name some [restaurants]{"entity": "object_type", "value": "restaurant"} please?
    - can you show me some [restaurants]{"entity": "object_type", "value": "restaurant"} options
    - list [German](cuisine) [restaurants]{"entity": "sobject_type", "value": "restaurant"}
    - do you have any [mexican](cuisine) [restaurants]{"entity": "object_type", "value": "restaurant"}?
    - do you know the [price range]{"entity": "attribute", "value": "price-range"} of [that one](mention)?
    - what [cuisine](attribute) is [it](mention)?
    - do you know what [cuisine](attribute) the [last one]{"entity": "mention", "value": "LAST"} has?
    - does the [first one]{"entity": "mention", "value": "1"} have [outside seating]{"entity": "attribute", "value": "outside-seating"}?
    - what is the [price range]{"entity": "attribute", "value": "price-range"} of [Berlin Burrito Company](restaurant)?
    - what about [I due forni](restaurant)?
    - can you tell me the [price range](attribute) of [that restaurant](mention)?
    - what [cuisine](attribute) do [they](mention) have?

[znat]

Closing as resolved with #818