pgsql: Document "B" and "us" as accepted units in postgres.conf.sample

Document "B" and "us" as accepted units in postgres.conf.sample

In postgresql.conf, memory and file size GUCs can be specified with "B"
(bytes) as of b06d8e58b. Likewise, time GUCs can be specified with "us"
(microseconds) as of caf626b2c. Update postgres.conf.sample to reflect
that fact.

Pavel Luzanov

Backpatch to v12, which is the earliest version that allows both of
these units. A separate commit will document the "B" case for v11.

Discussion: https://www.postgresql.org/message-id/flat/f10d16fc-8fa0-1b3c-7371-cb3a35a13b7a%40postgrespro.ru

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/bb95feabb8572f5069ad37763707862af5a81942

Modified Files
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src/backend/utils/misc/postgresql.conf.sample | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)