tweak grammar

Author: tbrowder

doc/Type/Proc.pod6

@@ -109,14 +109,14 @@ if the process it ran exited unsuccessfully.
 
     method spawn(*@args ($, *@), :$cwd = $*CWD, Hash() :$env = %*ENV --> Bool:D)
 
-Runs the C<Proc> object with the given command, argument list, working directory
+Runs the C<Proc> object with the given command, argument list, working directory,
 and environment.
 
 =head2 method shell
 
     method shell($cmd, :$cwd = $*CWD, :$env --> Bool:D)
 
-Runs the C<Proc> object with the given command and environment which is passed
+Runs the C<Proc> object with the given command and environment which are passed
 through to the shell for parsing and execution.
 
 =head2 method command