docs: OpenTelemetry's document is out of date

[juzhiyuan]

Current State

1. Visit this plugin's document[1][2].
2. Check additional_attributes[0] field: It's required according to the document.
3. Check this plugin's schema[3]. This field needs at least 1 item.
4. Visit this plugin's document[1][2], and check How-to-enable section[4], this sample doesn't contain additional_attributes field.

[1] master branch: https://apisix.apache.org/docs/apisix/next/plugins/opentelemetry
[2] 2.14 version: https://apisix.apache.org/docs/apisix/plugins/opentelemetry
[3] https://github.com/apache/apisix/blob/master/apisix/plugins/opentelemetry.lua#L166-L171
[4] https://apisix.apache.org/docs/apisix/plugins/opentelemetry/#how-to-enable

Desired State

I'm unsure which one is correct: the attributes part or How to enable?

Also, please help check the whole document's content. Not sure if there have other misleading or wrong contents.

Other

1. PR: feat: add opentelemetry plugin #6119
2. Guide: https://opentelemetry.io/blog/2022/apisix/

[juzhiyuan]

Also, I suggest adding a link to it to the documentation, like https://opentelemetry.io/blog/2022/apisix/

[guitu168]

The documentation should say that if additional_attributes is enabled then additional_attributes[0] needs to be set. We can change the additional_attributes[0] attribute description.

[github-actions]

This issue has been marked as stale due to 350 days of inactivity. It will be closed in 2 weeks if no further activity occurs. If this issue is still relevant, please simply write any comment. Even if closed, you can still revive the issue at any time or discuss it on the dev@apisix.apache.org list. Thank you for your contributions.

[github-actions]

This issue has been closed due to lack of activity. If you think that is incorrect, or the issue requires additional review, you can revive the issue at any time.