feat: 支持添加自定义内容用于follow认证 & 支持封面图 #36

[forrany]

尝试解决 #36

1. 添加自定义内容，追加在最后，用于 follow 订阅认证

2. 对于封面图无法识别的问题，follow会自动抓取内容的第一个图片作为封面，因此尝试通过meta抓取封面图

[f2c-ci-robot]

Adding the "do-not-merge/release-note-label-needed" label because no release-note block was detected, please follow our release note process to remove it.

Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[f2c-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
Once this PR has been reviewed and has the lgtm label, please assign guqing for approval. For more information see the Kubernetes Code Review Process.

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[Rising-Galaxy]

希望能添加自定义内容，追加在最后，或者是能够更改 字段用于 follow 订阅认证

[guqing]

Hi @Rising-Galaxy , 感谢你的贡献，在 #39 中我们重写了 feed 插件并已经完善了，因此此 PR 不再适合当前的场景，因此我将关闭此 PR

[guqing]

希望能添加自定义内容，追加在最后，或者是能够更改 字段用于 follow 订阅认证

在最新的代码中已经支持，等待 1.4.0 版本发布，参考 #39