docs: `sv.add` Drizzle ORM options for `client`

Turns out this is wrong:

await sv.add({
  cwd,
  addons: {
    drizzle: sv.officialAddons.drizzle,
  },
  options: {
    drizzle: { database: "sqlite", sqlite: "client-sqlite3" },
  },
  packageManager: "pnpm",
});

This is the fix:

- drizzle: { database: "sqlite", client: "better-sqlite3" },
+ drizzle: { database: "sqlite", sqlite: "better-sqlite3" },

I've been using a client key to match the CLI script:

npx sv add drizzle="database:postgresql+client:postgres.js"

I did name this as a docs issue, but would prefer the API to match CLI.

Review the sv.add options example and the sv add drizzle=... CLI syntax shown in the issue. Confirm whether the documented key or API should change, then update the relevant documentation or API behavior so the SQLite client option uses one consistent name and verify the examples.