minor #9472 [Console] Updated the style of the new "box" table (javiereguiluz)

This PR was merged into the master branch.

Discussion
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[Console] Updated the style of the new "box" table

This fixes #9456.

Commits
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62b4cc4 Updated the style of the new "box" table

Author: javiereguiluz

components/console/helpers/table.rst

@@ -152,14 +152,14 @@ which outputs:
 
 .. code-block:: text
 
-    ┼───────────────┼──────────────────────────┼──────────────────┼
+    ┌───────────────┬──────────────────────────┬──────────────────┐
     │ ISBN          │ Title                    │ Author           │
-    ┼───────────────┼──────────────────────────┼──────────────────┼
+    ├───────────────┼──────────────────────────┼──────────────────┤
     │ 99921-58-10-7 │ Divine Comedy            │ Dante Alighieri  │
     │ 9971-5-0210-0 │ A Tale of Two Cities     │ Charles Dickens  │
     │ 960-425-059-0 │ The Lord of the Rings    │ J. R. R. Tolkien │
     │ 80-902734-1-6 │ And Then There Were None │ Agatha Christie  │
-    ┼───────────────┼──────────────────────────┼──────────────────┼
+    └───────────────┴──────────────────────────┴──────────────────┘
 
 .. versionadded:: 4.1
     The ``box`` style was introduced in Symfony 4.1.