Doc: dev-expr description updated

doc/Expr.adoc

@@ -40,17 +40,19 @@ Here are some examples of execution.
 ----
 # Assume the expr source directory. Type 'exit' or Ctrl+D to quit the program.
 
-[user]$ tools/expr -- Expressions calculator v1.6.1,2024/05/06 (celestino.amoroso@portale-stac.it)
+[user]$ tools/expr -- Expressions calculator v1.7.0,2024/05/08 (celestino.amoroso@portale-stac.it)
 	Type help to get the list of command.
 	See also https://git.portale-stac.it/go-pkg/expr/src/branch/main/README.adoc
 
 >>> help
 --- REPL commands:
+        base -- Set the integer output base: 2, 8, 10, or 16
+        exit -- Exit the program
         help -- Show command list
           ml -- Enable/Disable multi-line output
         mods -- List builtin modules
+      source -- Load a file as input
          tty -- Enable/Disable ansi output <1>
-        exit -- Exit the program
 
 --- Command line options:
     -b <builtin>       Import builtin modules.
@@ -62,6 +64,8 @@ Here are some examples of execution.
     -m, --modules      List all builtin modules
     -p                 Print prefix form
     -t                 Print tree form <2>
+
+>>> 
 ----
 
 <1> Only available for single fraction values