npm Metadata plugin

```js
import npm_metadate from "drsensor/lume-plugins/npm_metadata.ts"
import lume from "lume/mod.ts"

import package from "./my-lib/package.ts"

export default lume()

.use(npm_metadata({
output: [".", "my-lib"], //--> ./_site/package.json and ./_site/my-lib/package.json
metadata: package,
}))
```
or
```js
.use(npm_metadata("./my-lib/package.ts"))
```
which default output into:
* *./package.json* - for github indexing (only if npm_metadata() used once)
* *./_site/my-lib/package.json* - publishing nightly version