Hanami contributors

All malin-as commits

Add documentation for the hanami new --template option.hanami.github.io
Fix the singular of "exercises" (#228)utils
Add a paragaph about Content Security Policy settings when dealing with CDNs.hanami.github.io
Fix call to HTTP method named `unklink` (#153)router
Fix README's missing parameters in a nested resources example. (#154)router
Fix the documentation of the `select` helper method.helpers