Update challenge headline and refresh ISCC URLs and metadata

Reword challenge section title for clarity. Update ISCC homepage and
spec URLs to current domains, remove outdated concept and component
URLs.

Author: titusz

_data/challenge.yml

@@ -5,7 +5,7 @@
 # Items support optional `strong` for the bold lead-in phrase.
 # ─────────────────────────────────────────────────────────────────
 
-section_title: "Making Bioimaging Data AI-Ready<br/>with Content-Based Identifiers"
+section_title: "Enhancing AI-Readiness of Bioimaging Data<br/>with Content-Based Identifiers"
 
 cards:
   - id: challenge

_data/iscc.yml

@@ -9,9 +9,8 @@ standard:
   short: ISCC
   iso: ISO 24138
   iso_url: https://www.iso.org/standard/77899.html
-  homepage_url: https://iscc.codes/
-  spec_url: https://iscc.codes/specification/
-  concept_url: https://iscc.codes/concept/
+  homepage_url: https://iscc.io
+  spec_url: https://ieps.iscc.codes
   description: >
     A standardised (ISO 24138) multi-component fingerprint for various
     media types and file formats. Computed from the asset itself — it
@@ -48,16 +47,12 @@ iscc_id:
     - number: 1
       name: ISCC-CODE
       description: Algorithmically generated, reproducible data descriptor.
-      url: https://github.com/iscc/iscc-core
     - number: 2
       name: Actor
       description: Entity owning the ISCC-ID.
-      url: https://github.com/iscc/iscc-registry
     - number: 3
       name: Creation Time
       description: Timestamp of ISCC-ID creation.
-      url:
     - number: 4
       name: Metadata URL
       description: URL for accessing ISCC-ID metadata.
-      url: https://iscc.codes/specification/