Add documentation for the Kubelet Stats receiver (kubeletstatsreceiver)

[alexandra5000]

What does this PR do?

This PR adds a new component page for the Kubelet Stats receiver (kubeletstatsreceiver).

Why is it important?

The receiver is part of the upstream OpenTelemetry Collector and included in the EDOT Collector distribution, and as such should be documented.

Checklist

• I have read and understood the pull request guidelines of this project.
  - [ ] My code follows the style guidelines of this project
  - [ ] I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
  - [ ] I have made corresponding change to the default configuration files
  - [ ] I have added tests that prove my fix is effective or that my feature works
  - [ ] I have added an entry in ./changelog/fragments using the changelog tool
  - [ ] I have added an integration test or an E2E test

Disruptive User Impact

None

Related issues

• Closes #1029

[mergify]

This pull request does not have a backport label. Could you fix it @alexandra5000? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-./d./d is the label that automatically backports to the 8./d branch. /d is the digit
• backport-active-all is the label that automatically backports to all active branches.
• backport-active-8 is the label that automatically backports to all active minor branches for the 8 major.
• backport-active-9 is the label that automatically backports to all active minor branches for the 9 major.