Update Validation container docs

[nickclyde]

PULL REQUEST

Summary

Update Validation container docs
Also fixes description.md for all containers to point at latest tag rather than main

Related Issue

Fixes #490

[codecov]

Codecov Report

Merging #579 (4730e64) into main (f7a8166) will decrease coverage by 0.01%.
The diff coverage is n/a.

❗ Current head 4730e64 differs from pull request most recent head b156cb5. Consider uploading reports for the commit b156cb5 to get more accurate results

@@            Coverage Diff             @@
##             main     #579      +/-   ##
==========================================
- Coverage   96.50%   96.49%   -0.01%     
==========================================
  Files          45       45              
  Lines        2488     2485       -3     
==========================================
- Hits         2401     2398       -3     
  Misses         87       87              

Flag	Coverage Δ
unit-tests	96.49% <ø> (-0.01%)	⬇️

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see 1 file with indirect coverage changes

[emmastephenson]

Looks great, thanks Nick!