[Doc] Remove duplicate pages

[candlerb]

There are stale/overlapping pages under site2/docs:

• functions-debug.md
• functions-debugging.md << obsolete, not linked

and

• functions-deploy.md
• functions-deploying.md << obsolete, linked only from deploy-bare-metal

This patch removes the obsolete pages, and updates the links in deploy-bare-metal (also removing a link to functions-state.md which is also gone)

[sijie]

@tuteng @jennifer88huang : since you are fixing the links between different versions of documentation, can you please take a look at this pull request?

[tuteng]

@tuteng @jennifer88huang : since you are fixing the links between different versions of documentation, can you please take a look at this pull request?

I will try my best to fix this problem this afternoon and then create a pr.

[Jennifer88huang-zz]

@candlerb Thank you very much for your contributions. I suggest we'd better not remove the two obsolete files currently.
There is a list of obsolete files, @tuteng is fixing them this afternoon, and he has come up with solution on how to solve the link issues.

[Jennifer88huang-zz]

Suggested change

	Check if the function runs as expected by [triggering](functions-deploy.md#triggering-pulsar-functions) the function.
	Check if the function runs as expected by [triggering](functions-deploy.md#trigger-pulsar-functions) the function.

[Jennifer88huang-zz]

@candlerb Since there are more obsolete files, @tuteng submit a PR to fix it in #5700 , could you please also check #5700 ? His solution includes the files in this PR.

[candlerb]

I don't understand #5700 at all; it says it's being done because of limitations of docusaurus, which is a platform I don't know.

[Jennifer88huang-zz]

@candlerb Never mind. Let me explain in details.
Pulsar website use docusaurus as framework.
Previously, we've tried to remove all those obsolete files, and it resulted to link failure for versions earlier than 2.4.1. And then @tuteng added all those obsolete files back to the docs folder. There was no link issues for the current version and earlier versions. However, contributors felt confused why those obsolete files are there in the master, and not sure which file to update.

We're trying to remove all those obsolete files, yet it would inevitably affect links in earlier versions. Those obsolete files were used in earlier versions, and we have to maintain doc content in the earlier versions unchanged, and keep only latest doc content in the master. So @tuteng comes with the solution: keep the obsolete files name in the master(with empty content), move the obsolete files and contents to earlier versions.

If you have any better idea on this, feel free to contact us.

[sijie]

Please don't merge this before #5700

[tuteng]

I don't understand #5700 at all; it says it's being done because of limitations of docusaurus, which is a platform I don't know.

Docusaurus is a framework with version management of documents https://docusaurus.io/docs/en/installation.
The sub-version depends on the main version. Observe the following id and original_id fields. If the main version file is deleted, the file under the subversion will not find the index. Users get a lot of Http 404 when viewing older versions of documents. However, if we don't delete the files and keep the contents under the main version, there will be many duplicate contents, which will lead to confusion when the contributors contribute. therefore, we delete the contents and only keep one header in order for the sub-version to have a correct index, the contributor only needs to update the contents in the main version.
@candlerb

functions-api.md
main version (latest version)

---
id: functions-api
title: The Pulsar Functions API
sidebar_label: API
---

Subversion, (old version)

---
id: version-2.4.0-functions-api
title: The Pulsar Functions API
sidebar_label: API
original_id: functions-api
---

[Jennifer88huang-zz]

@candlerb could you please update the suggestion in the deploy-bare-metal.md file, and resolve conflicting files, and then we can go on with the next step? Thank you.

[candlerb]

I withdraw this PR.