[Documentation]:  Split ngx-inform introduction page into two sections

The `ngx-inform` page needs to be divided into a `For business` and a `For developers` section.

- In the `For business` section, we explain that the inform package is used for common use-cases where an end-user needs to be informed by the application (tooltip, modal, etc.) in a fully WCAG compliant way.
- In the `For developers` section we use the existing documentation