docs: update the perception design document and the interface document

[miursh]

Description

Improve the documentation related to the perception module.

• Perception sub-components sescription: Add examples of object recognition and obstacle segmentation.
• Update perception output description

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[TakaHoribe]

LGTM

[github-actions]

Documentation URL: https://autowarefoundation.github.io/autoware-documentation/pr-499/
Modified URLs:

• https://autowarefoundation.github.io/autoware-documentation/pr-499/design/autoware-architecture/perception/
• https://autowarefoundation.github.io/autoware-documentation/pr-499/design/autoware-interfaces/components/perception/

[miursh]

@Shin-kyoto
I revised the wording. 8454221
Could you review again?

[Shin-kyoto]

LGTM