Quote the keys of the sass map variables

Due to the way sass works if you don't quote the maps you can have issues with map keys being other object types such as a color. e.g values like "red" getting converted into #f00 etc. This can be avoided by quoting the key.
### Current Output:

```
$theme: (
Primary: (
Ocean Blue: (
model: RGB,
type: 2,
rgb: (57, 84, 216),
code: 3954d8
),
Tree Green: (
model: RGB,
type: 2,
rgb: (154, 188, 47),
code: 9abc2f
)
)
);
```
### Suggested Output

```
$theme: (
"Primary": (
"Ocean Blue": (
"model": RGB,
"type": 2,
"rgb": (57, 84, 216),
"code": 3954d8
),
"Tree Green": (
"model": RGB,
"type": 2,
"rgb": (154, 188, 47),
"code": 9abc2f
)
)
);
```