## concat_string

### Instructions

Create a file `concat_string.py` that contains a function `concat` which takes in two strings as parameters and performs the following operations:

- Concatenates the two strings by adding a comma and space between them.

- Returns the resulting string.

### Usage

Here is an example of how to use the `concat` function in a `test.py` script:

```python
import concat_string
string1 = "Hello"
string2 = "World"
print(concat_string.concat(string1, string2))
```

Below is the expected output:

```console
$ python3 test.py
Hello, World
$
```

### References

[string concatenation](https://www.w3schools.com/python/ref_string_concatenation.asp)