* changing sample project to use microsoft health checks library
* update probes recipe
* Update probes.md
* changing probes doc
* give more description in '/' of sample service
* sample app and beggining of recipe
* fix link
* sample, recipe and schema docs
* change http failures to debug logs
* add model validation to probes and http prober
* add deserialization and validation tests
* license
* format
* PR fixes
* remove some Console.WriteLine's