Add full shop application: Go backend, PostgreSQL, Docker, Caddy and admin panel.

migrations/002_admins.sql

@@ -0,0 +1,6 @@
+CREATE TABLE IF NOT EXISTS admins (
+    id            SERIAL PRIMARY KEY,
+    email         VARCHAR(255) UNIQUE NOT NULL,
+    password_hash VARCHAR(255) NOT NULL,
+    created_at    TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);