docs suggestion, add a vector search failure mode checklist for RAG builders

hi maintainers, thanks for weaviate.

docs suggestion:
many RAG failures are actually vector search failure modes in disguise,
like near-duplicate collapse, metric mismatch, normalization issues, or index update skew.

proposal:
add a short checklist page, symptom-first, and map to likely causes.
taxonomy reference i use (open source):
https://github.com/onestardao/WFGY/blob/main/ProblemMap/README.md

minimal scope:

• 1 page doc, focus on "what users see" and "what to check first"
• link to existing weaviate docs for distance metrics, normalization, hybrid search weighting

if this aligns, i can draft the doc page and open a PR.

Start by reading the linked WFGY ProblemMap reference and the existing Weaviate documentation on distance metrics, normalization, and hybrid search weighting. Draft one symptom-first checklist page that maps what users see to likely causes and points to those existing pages; the work is done when the single-page checklist covers the proposed failure modes and links are in place.