vale: allow pluralized acronym initialization

E.g., "Large Language Models (LLMs)" permits the use of "LLM"

Signed-off-by: David Karlsson <35727626+dvdksn@users.noreply.github.com>

_vale/Docker/Acronyms.yml

@@ -5,7 +5,7 @@ level: warning
 ignorecase: false
 # Ensures that the existence of 'first' implies the existence of 'second'.
 first: '\b([A-Z]{2,5})\b'
-second: '(?:\b[A-Z][a-z]+ )+\(([A-Z]{2,5})\)'
+second: '(?:\b[A-Z][a-z]+ )+\(([A-Z]{2,5})s?\)'
 # ... with the exception of these:
 exceptions:
   - AGPL