#53 - Create API documentation

- Added links to sections
- Added simple C# webclient code example
- Corrected links to demo site (yet to be deployed)
#53 - Create API documentation

Fixing code formatting
#53 - Create API documentation

Modifying code sample
#53 - Create API documentation

Experimenting with using dotnetfiddle.net to host code samples
#53 - Create API documentation

Updating dotnetfiddle to return JSON string correctly
#53 - Create API documentation

Updating dotnetfiddle iframe code
#53 - Create API documentation

Updating dotnetfiddle iframe to include better code sample
#53 - Create API documentation

Adding dotnetfiddle example for 'Getting a single initialised feature switch'
#53 - Create API documentation

Adding dotnetfiddle code sample for 'Getting all initialised feature switch types'
#53 - Create API documentation

Added dotnetfiddle example for 'Updating an existing initiliased feature switch'
#53 - Create API documentation

Updated credits tag in MD
#53 - Create API documentation

Adding a cURL example for 'Updating an existing initiliased feature switch'