feat: support for multiline cells

[DenverCoder1]

Fixes #28

Example

from table2ascii import table2ascii as t2a, PresetStyle, Alignment

table = t2a(
    header=["Multiline\nHeader\nCell", "G", "Two\nLines", "R", "S"],
    body=[[1, "Alpha\nBeta\nGamma", 3, 4, "One\nTwo"]],
    footer=["A", "Footer\nBreak", 1, "Second\nCell\nBroken", 3],
    alignments=[Alignment.LEFT, Alignment.RIGHT, Alignment.CENTER, Alignment.LEFT, Alignment.CENTER],
    style=PresetStyle.ascii_box
)

print(table)

+-----------+--------+-------+--------+-----+
| Multiline |      G |  Two  | R      |  S  |
| Header    |        | Lines |        |     |
| Cell      |        |       |        |     |
+-----------+--------+-------+--------+-----+
| 1         |  Alpha |   3   | 4      | One |
|           |   Beta |       |        | Two |
|           |  Gamma |       |        |     |
+-----------+--------+-------+--------+-----+
| A         | Footer |   1   | Second |  3  |
|           |  Break |       | Cell   |     |
|           |        |       | Broken |     |
+-----------+--------+-------+--------+-----+