pgsql: Update .editorconfig and .gitattributes for postgresql.conf.samp

Update .editorconfig and .gitattributes for postgresql.conf.sample.

This commit updates .editorconfig and .gitattributes in preparation
for a follow-up commit that will modify this file to use spaces
instead of tabs.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/aReNUKdMgKxLqmq7%40nathan

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/aeebb49b7cfeff525fafe8ae105e091c923193fb

Modified Files
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.editorconfig  | 6 ++++++
.gitattributes | 1 +
2 files changed, 7 insertions(+)