doc: normalize Bash code block info strings

Prior to this commit, Bash fenced code blocks in Markdown files had
inconsistent info strings. This has been corrected to standardize on
the less-obscure variant.

PR-URL: https://github.com/nodejs/node/pull/33510


Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>