Обсуждение: pgsql: Standardize references to Zstandard as

Standardize references to Zstandard as <productname>

Some places used ZSTD, which isn't widely used anywhere.  Use ZSTD only
to refer to the environment variable; use zstd (all lowercase) to refer
to the utility.

Per complaint from Justin Pryzby.

Discussion: https://postgr.es/m/20220414003301.GT26620@telsasoft.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/586955dddecc95e0003262a3954ae83b68ce0372

Modified Files
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doc/src/sgml/install-windows.sgml | 6 +++---
doc/src/sgml/installation.sgml    | 4 ++--
2 files changed, 5 insertions(+), 5 deletions(-)