pgsql: doc: Use proper tags in pg_overexplain documentation.

doc: Use proper tags in pg_overexplain documentation.

The pg_overexplain documentation previously used the <literal> tag for
some file names, struct names, and commands. Update the markup to
use the more appropriate tags: <filename>, <structname>, and <command>.

Backpatch to v18, where pg_overexplain was introduced.

Author: Fujii Masao <masao(dot)fujii(at)gmail(dot)com>
Reviewed-by: Shixin Wang <wang-shi-xin(at)outlook(dot)com>
Reviewed-by: Chao Li <li(dot)evan(dot)chao(at)gmail(dot)com>
Discussion: https://postgr.es/m/CAHGQGwEyYUzz0LjBV_fMcdwU3wgmu0NCoT+JJiozPa8DG6eeog@mail.gmail.com
Backpatch-through: 18

Branch
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REL_18_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/02a0f385fa980c1eb14947936161123b4848fe9b

Modified Files
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doc/src/sgml/pgoverexplain.sgml | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)