pgsql: doc: Move remove_temp_files_after_crash to section for developer

doc: Move remove_temp_files_after_crash to section for developer options

The main goal of this option is to allow inspecting temporary files for
debugging purposes, so moving the parameter there is natural.

Oversight in cd91de0.

Reported-by: Justin Pryzby
Author: Euler Taveira
Discussion: https://postgr.es/m/20210612004347.GP16435@telsasoft.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/797b0fc0b078c7b4c46ef9f2d9e47aa2d98c6c63

Modified Files
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doc/src/sgml/config.sgml                      | 41 +++++++++++++--------------
src/backend/utils/misc/guc.c                  |  5 ++--
src/backend/utils/misc/postgresql.conf.sample |  2 --
3 files changed, 22 insertions(+), 26 deletions(-)