Add term 'workflow introspection' to docs (nextflow-io#5620) [ci skip]

I keep searching for this specific term and it's been removed. Apparently I wasn't the only one.

Signed-off-by: Phil Ewels <phil.ewels@seqera.io>
Signed-off-by: adamrtalbot <12817534+adamrtalbot@users.noreply.github.com>

Author: ewels

docs/reference/stdlib.md

@@ -10,7 +10,7 @@ This page describes the built-in constants, functions, and types provided by Nex
 
 ### Constants
 
-The following constants are globally available in a Nextflow script:
+The following constants are globally available in a Nextflow script for workflow introspection:
 
 `baseDir`
 : :::{deprecated} 20.04.0