Grafserv imports Ruru which breaks bundling
1. I am deploying to AWS lambda, which involves bundling
2. `grafserv` imports `ruru` 
3. `ruru` does all kinds of bundler-incompatible things like trying to `readFileSync` `package.json` etc


The stack looks like

```
Error: ENOENT: no such file or directory, open '/var/package.json'
    at Object.openSync (node:fs:603:3)
    at readFileSync (node:fs:471:35)
    at mapIterator (/node_modules/ruru/src/server.ts:7:3)
    at file:///var/task/pglambda-v2.mjs:9:495
    at getGrafservHooks (/node_modules/grafserv/src/middleware/graphiql.ts:2:1)
    at file:///var/task/pglambda-v2.mjs:9:495
    at optionsFromConfig (/node_modules/grafserv/src/core/base.ts:22:1)
    at file:///var/task/pglambda-v2.mjs:9:495
    at <anonymous> (/node_modules/grafserv/src/index.ts:1:1)
    at file:///var/task/pglambda-v2.mjs:9:495
```

As a first pass, I suggest making `ruru` lazily evaluate non-bundleable code so that it can be imported in bundled contexts without error. 