minor #19950 🎨 Fix precedence table rendering (homersimpsons)

This PR was submitted for the 7.1 branch but it was merged into the 6.4 branch instead.

Discussion
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:art: Fix precedence table rendering

Use rst grid to get the correct layout. `list-table` directive is not supported.

This is a follow-up of #19894 which itself was a follow-up of !19860.

The rendered HTML is now correct

/cc `@OskarStark` `@javiereguiluz`

Commits
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f6b21f4 🎨 Fix precedence table rendering

Author: xabbuh

reference/formats/expression_language.rst

@@ -436,26 +436,38 @@ parentheses in your expressions (e.g. ``(1 + 2) * 4`` or ``1 + (2 * 4)``.
 The following table summarizes the operators and their associativity from the
 **highest to the lowest precedence**:
 
-=======================================================  =============
-Operators                                                associativity
-=======================================================  =============
-``-``, ``+`` (unary operators that add the number sign)  none
-``**``                                                   right
-``*``, ``/``, ``%``                                      left
-``not``, ``!``                                           none
-``~``                                                    left
-``+``, ``-``                                             left
-``..``                                                   left
-``==``, ``===``, ``!=``, ``!==``, \                      left
-``<``, ``>``, ``>=``, ``<=``, \
-``not in``, ``in``, ``contains``, \
-``starts with``, ``ends with``, ``matches``
-``&``                                                    left
-``^``                                                    left
-``|``                                                    left
-``and``, ``&&``                                          left
-``or``, ``||``                                           left
-=======================================================  =============
++----------------------------------------------------------+---------------+
+| Operators                                                | Associativity |
++==========================================================+===============+
+| ``-`` , ``+`` (unary operators that add the number sign) | none          |
++----------------------------------------------------------+---------------+
+| ``**``                                                   | right         |
++----------------------------------------------------------+---------------+
+| ``*``, ``/``, ``%``                                      | left          |
++----------------------------------------------------------+---------------+
+| ``not``, ``!``                                           | none          |
++----------------------------------------------------------+---------------+
+| ``~``                                                    | left          |
++----------------------------------------------------------+---------------+
+| ``+``, ``-``                                             | left          |
++----------------------------------------------------------+---------------+
+| ``..``                                                   | left          |
++----------------------------------------------------------+---------------+
+| ``==``, ``===``, ``!=``, ``!==``,                        | left          |
+| ``<``, ``>``, ``>=``, ``<=``,                            |               |
+| ``not in``, ``in``, ``contains``,                        |               |
+| ``starts with``, ``ends with``, ``matches``              |               |
++----------------------------------------------------------+---------------+
+| ``&``                                                    | left          |
++----------------------------------------------------------+---------------+
+| ``^``                                                    | left          |
++----------------------------------------------------------+---------------+
+| ``|``                                                    | left          |
++----------------------------------------------------------+---------------+
+| ``and``, ``&&``                                          | left          |
++----------------------------------------------------------+---------------+
+| ``or``, ``||``                                           | left          |
++----------------------------------------------------------+---------------+
 
 Built-in Objects and Variables
 ------------------------------