Add support to display Grid Table well formatted in preview

[RedCali]

Grid tables can be used to:

• easily merge cells / columns
• define the width of columns

by draw the table accordingly without the need of any additional attributes

its already supported by renders like

• Pandoc
• Markdig

: Sample grid table.

+---------------+---------------+--------------------+
| Fruit         | Price         | Advantages         |
+===============+===============+====================+
| Bananas       | $1.34         | - built-in wrapper |
|               |               | - bright color     |
+---------------+---------------+--------------------+
| Oranges       | $2.10         | - cures scurvy     |
|               |               | - tasty            |
+---------------+---------------+--------------------+

:samples with spans:

+---+---+---+
| AAAAA | B |
+---+---+ B +
| D | E | B |
+ D +---+---+
| D | CCCCC |
+---+---+---+

+---+---+---+
| AAAAA | B |
+ AAAAA +---+
| AAAAA | C |
+---+---+---+
| D | E | F |
+---+---+---+

[github-actions[bot]]

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