repl: improve doc for disabling REPL history on Windows

Environment variables with empty values are not permitted on Windows. As such, to disable persistent REPL history one or more spaces should be used. Node will trim whitespace from the variable, resulting in a blank variable at runtime and the desired behaviour. PR-URL: #25672Fixes: #25661 Reviewed-By: Jeremiah Senkpiel <[email protected]> Reviewed-By: Vse Mozhet Byt <[email protected]> Reviewed-By: Ruben Bridgewater <[email protected]> Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Richard Lau <[email protected]> Reviewed-By: Anto Aravinth <[email protected]> Reviewed-By: Bartosz Sosnowski <[email protected]>

Author: ralish

doc/api/repl.md

@@ -540,8 +540,10 @@ environment variables:
 
 -`NODE_REPL_HISTORY` - When a valid path is given, persistent REPL history
  will be saved to the specified file rather than `.node_repl_history` in the
- user's home directory. Setting this value to `''` will disable persistent
- REPL history. Whitespace will be trimmed from the value.
+ user's home directory. Setting this value to `''` (an empty string) will
+ disable persistent REPL history. Whitespace will be trimmed from the value.
+ On Windows platforms environment variables with empty values are invalid so
+ set this variable to one or more spaces to disable persistent REPL history.
 -`NODE_REPL_HISTORY_SIZE` - Controls how many lines of history will be
  persisted if history is available. Must be a positive number.
 **Default:**`1000`.