What

Create a documentation for the iOS self defence feature. It should cover:

• Prerequisites
• how to use the iOS security sdk
• what are the provided checks
• how to create new types of checks
• how to invoke the checks
• how to send the metrics

It should be similar to the android one: https://github.com/aerogear/aerogear-android-sdk/blob/master/docs/getting-started/auth-self-defence-checks.adoc