feat: Support browser-level image lazy-loading

[sy-records]

Summary

Support browser-level image lazy-loading.

What kind of change does this PR introduce? (check at least one)

• [ ] Bugfix
• [x] Feature
• [ ] Code style update
• [ ] Refactor
• [x] Docs
• [ ] Build-related changes
• [ ] Repo settings
• [ ] Other, please describe:

If changing the UI of default theme, please provide the before/after screenshot:

Does this PR introduce a breaking change? (check one)

• [ ] Yes
• [x] No

If yes, please describe the impact and migration path for existing applications:

The PR fulfills these requirements:

• [x] When resolving a specific issue, it's referenced in the PR's title (e.g. fix #xxx[,#xxx], where "xxx" is the issue number)

resolve #1431

You have tested in the following browsers: (Providing a detailed version will be better.)

• [x] Chrome
• [ ] Firefox
• [ ] Safari
• [ ] Edge
• [ ] IE

If adding a new feature, the PR's description includes:

• [ ] A convincing reason for adding this feature
• [x] Related documents have been updated
• [ ] Related tests have been updated

To avoid wasting your time, it's best to open a feature request issue first and wait for approval before working on it.

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[anikethsaha]

LGTM can you add a test case.

[sy-records]

@anikethsaha done

[jhildenbiddle]

@sy-records, @anikethsaha, @Koooooo-7 --

This needs further discussion. Please hold off merging until I can provide detailed feedback...

[jhildenbiddle]

@sy-records, @anikethsaha, @Koooooo-7 --

Two quick suggestions regarding issues and PRs moving forward:

1. We shouldn't be creating enhancement requests (#1431) immediately followed by a PR (this one) without some discussion taking place. The purpose of creating a new issue/feature request is to allow others to discuss the enhancement before code is written. If the implementation is critical to the discussion, a draft PR can be created and linked to in the issue.

2. The titles of issues and feature requests shouldn't dictate implementation. The title of #1431 would be better written as "Support lazy-loading of images". Native lazy-loading is just one of many ways to accomplish the goal. The goal of an enhancement (like lazy-loading) should be to solve a problem or provide additional value, not to "do a technical thing".