Docs: fix five stale internal links after slug renames
Docs: fix five stale internal links after slug renames
Five internal links in the Models docs now point at the correct pages:
- Electron model card API-reference link (
electron-chat-completions) - LLM overview + quickstart
migrate-from-openailink - Pulse STT realtime features
age-and-gender-detectionlink - Lightning v3.1 Pro model card
voice-cloning/how-to-vc-apilink
Also updates the fern/docs.yml redirects table so old URLs keep resolving. No product behavior change.

