Add Component page under Key Concepts

[dhmlau]

Description / Steps to reproduce / Feature proposal

In https://loopback.io/doc/en/lb4/Crafting-LoopBack-4.html#rebuilding-loopback-experience-on-top-of-the-new-core, the link for Component is broken.

Talked to @raymondfeng , we should have a page for Component under concepts.

Related to #1908

Acceptance Criteria

• Create a Component page under Key concepts. Describe the functionality and interface of a Component class on it.
• Refactor the Using components page by moving relevant content to Component page.
• Link the Component page from Concepts page.

[bajtos]

As a short-term solution to fix the broken link, I am proposing to point readers to https://loopback.io/doc/en/lb4/Extending-LoopBack-4.html for now as part of this story, and create a new story to write Component page under Concepts.

[dhmlau]

Created PR #2361 to fix the broken link, and updated the Acceptance Criteria.

[dhmlau]

@raymondfeng , what content do you have in mind for that Component page? given that we have https://loopback.io/doc/en/lb4/Using-components.html. Thanks.

[dhmlau]

Fixed the broken link through PR #2361. Moving this out of TOB.

[dhmlau]

I forgot that we need to estimate this task first.
@hacksparrow, could you please edit the acceptance criteria? Thanks!

[emonddr]

@dhmlau

In https://loopback.io/doc/en/lb4/Crafting-LoopBack-4.html#rebuilding-loopback-experience-on-top-of-the-new-core, the link for Component is broken.

I don't see the word Component on the url you mentioned. Do you mean it is missing somewhere on the left side bar?

[dhmlau]

Sorry.. I think I was referring to the section above. Should be here: https://loopback.io/doc/en/lb4/Crafting-LoopBack-4.html#deep-dive-into-loopback-4-extensibility. But I fixed the broken link to point to the using-component.md.

[dhmlau]

Closing as resolved because PR #2702 has merged.