Add diagnosis for NodeFilesystemAlmostOutOfFiles

[awcodify]

Description

Add documentation to diagnose NodeFilesystemAlmostOutOfFiles

Type of change

What type of changes does your code introduce to the Prometheus operator? Put an x in the box that apply.

• [ ] CHANGE (fix or feature that would cause existing functionality to not work as expected)
• [ ] FEATURE (non-breaking change which adds functionality)
• [ ] BUGFIX (non-breaking change which fixes an issue)
• [ ] ENHANCEMENT (non-breaking change which improves existing functionality)
• [X] NONE (if none of the other choices apply. Example, tooling, build system, CI, docs, etc.)

Changelog entry

add dcos

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