Clean up and document interfaces exposed to users

[hackerwins]

Description:

Clean up and document interfaces exposed to users.

At #173 we only exposed documents that are exposed to the user. After doing this, we find that fewer comments are written in the interfaces exposed to the user.

Let's check the items below:

• Comment the interfaces exposed to the user
• Add @internal to expose unnecessary interfaces
• Add @public to the interfaces we need to expose but are missing and export them in the entry file.

Why:

Users experience the product through the interfaces. Therefore, it is very important to clean up the exposed interfaces.