Dominic Fallows 2d45354af5 Export BaseLine to fix cannot be named ts4023 ...

Export the `BaseLine` interface to fix TS `cannot be named errors`, for example: 

```bash
Exported variable 'scale' has or is using name 'BaseLine' from external module "node_modules/@types/typography/index" but cannot be named.ts(4023)
```

2019-01-05 16:59:47 +00:00

..

index.d.ts

…

tsconfig.json

…

tslint.json

…

typography-tests.ts

…