Function startsEnds

startsEnds(source: string, start: string, end?: string): boolean
Returns true if source starts and ends with start and end. Case-sensitive. If end is omitted, the the start value will be used.
```
startsEnds(`This is a string`, `This`, `string`); // True
startsEnds(`This is a string`, `is`, `a`); // False
starsEnds(`test`, `t`); // True, starts and ends with 't'
```
Parameters
- source: string
  String to search within
- start: string
  Start
- end: string = start
  End (if omitted, start will be looked for at end as well)
Returns boolean
True if source starts and ends with provided values.