Add a link to documentation on OOM task failure

[Kanan B (kananb)]

Summary of the Pull Request

Add more logging to OOM task failures, including a link to our docs on such events.

PR Checklist

• Applies to work item: #xxx
• CLA signed. If not, go over here and sign the CLI.
• Tests added/passed
• Requires documentation to be updated
• I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx

Info on Pull Request

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Validation Steps Performed

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[Codecov Comments Bot (codecov-commenter)]

Codecov Report

Merging #3602 (71d870d) into main (d50fd48) will increase coverage by 1.06%.
The diff coverage is 0.00%.

@@ Coverage Diff @@## main #3602 +/- ##
==========================================
+ Coverage 39.95% 41.02% +1.06% 
==========================================
Files 303 303 Lines 37724 37736 +12 Branches 1738 1738 ==========================================
+ Hits 15073 15481 +408 + Misses 22330 21934 -396 
Partials 321 321 

Files	Coverage Δ
src/agent/onefuzz-task/src/managed/cmd.rs	0.00% <0.00%> (ø)

... and 11 files with indirect coverage changes