Fixed README display on GitHub & Fixed the JSON output

Previous output:
```
[
{"id" : "max", {"area": "26.2188", "perimeter" : "52.25"}},
{"id" : "sup", {"area": "26.2188", "perimeter" : "52.25"}},
{"id" : "med", {"area": "23.9531", "perimeter" : "50.25"}},
{"id" : "inf", {"area": "21.8906", "perimeter" : "48.5"}},
{"id" : "min", {"area": "21.8906", "perimeter" : "48.5"}}
]
```
this isn't valid JSON: each member of the array is a hashmap, which is a set of (key: values) pairs. If `"id": "max"` is a correct key/value pair, ` {"area": "26.2188", "perimeter" : "52.25"}` isn't (it is only a value, it needs a key!)

Updated output:
```
[
{ "max": {"area": "26.2188", "perimeter" : "52.25"}},
{ "sup": {"area": "26.2188", "perimeter" : "52.25"}},
{ "med": {"area": "23.9531", "perimeter" : "50.25"}},
{ "inf": {"area": "21.8906", "perimeter" : "48.5"}},
{ "min": {"area": "21.8906", "perimeter" : "48.5"}}
]
```