Descriptions are inline markdown; Feature.link withdrawn

Alternative and feature descriptions render links, emphasis and code
(pulldown-cmark, html feature only). Block structure flattens to one
paragraph, raw HTML is dropped, link targets are limited to https,
mailto and site-relative paths. A link belongs in the prose, so the
title-link field shipped in 0.3.7 goes before anyone uses it.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Cargo.toml

@@ -12,6 +12,9 @@ leptos_meta = { version = "0.8" }
 leptos_router = { version = "0.8" }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
+# Inline markdown for content descriptions (links, emphasis, code) -
+# runs on both server and client renders, so not feature-gated.
+pulldown-cmark = { version = "0.13", default-features = false, features = ["html"] }
 
 # --- server only ---
 leptos_axum = { version = "0.8", optional = true }