♻️(yhub) maintain database schema using npm run init-db

The yhub database schema have new update and will probably be modified
in the future. We don't want to maintain this sql schema in the Docs
repo, we want to reuse what is directly made in the yhub project. For
this we reuse the existing bin/init-db.js script

docker/files/yhub/initdb/01-yhub.sql

@@ -1,14 +0,0 @@
--- Column-for-column from yhub bin/init-db.js (unquoted identifiers so
--- case-folding matches yhub's persistence.js queries).
-CREATE TABLE IF NOT EXISTS yhub_ydoc_v1 (
-    org             text,
-    docid           text,
-    branch          text,
-    t               text,
-    created         INT8,
-    gcDoc           bytea,
-    nongcDoc        bytea,
-    contentmap      bytea,
-    contentids      bytea,
-    PRIMARY KEY     (org,docid,branch,t)
-);