Rename AdventureLog to Voyage and add fork attribution

- Replace all AdventureLog references with Voyage across ~102 files
  (7 case variants: AdventureLog, adventurelog, Adventurelog, ADVENTURELOG,
  AdventUrelog, AdventureLOG, adventure-log, adventure_log)
- Rename brand, static, and documentation assets to use voyage naming
- Rename install_adventurelog.sh → install_voyage.sh
- Update README.md and voyage_overview.md to credit AdventureLog as
  the upstream project and Sean Morley as its original creator

.github/.docker-compose-database.yml

@@ -1,7 +1,7 @@
 services:
   db:
     image: postgis/postgis:15-3.3
-    container_name: adventurelog-db
+    container_name: voyage-db
     restart: unless-stopped
     ports:
       - "127.0.0.1:5432:5432"