fix(table): set widths (#758)

I'm not sure about this, as it might be slow in big tables...

This will go through all rows, calculate their widths, and set it as the
column width if none was provided with `-w`.

```console
$ echo -e "a,b\naaaaaaaaaaaaaaaaaaaaaaa,bbbbbbbbbbbbbbbb" | gum table
 a  b
 …  …

$ echo -e "a,b\naaaaaaaaaaaaaaaaaaaaaaa,bbbbbbbbbbbbbbbb" | gum table
 a                        b
 aaaaaaaaaaaaaaaaaaaaaaa  bbbbbbbbbbbbbbbb

$ echo -e "a,b\naaaaaaaaaaaaaaaaaaaaaaa,bbbbbbbbbbbbbbbb" | gum table -w 5,5
 a      b
 aaaa…  bbbb…

```

closes #285

table/command.go

@@ -89,6 +89,14 @@ func (o Options) Run() error {
 		if len(row) > len(columns) {
 			return fmt.Errorf("invalid number of columns")
 		}
+		for i, col := range row {
+			if len(o.Widths) == 0 {
+				width := lipgloss.Width(col)
+				if width > columns[i].Width {
+					columns[i].Width = width
+				}
+			}
+		}
 		rows = append(rows, table.Row(row))
 	}