docs: document show-vulnerable-paths in help

help/help.txt

@@ -31,6 +31,10 @@ Options:
   --trust-policies ... Applies and uses ignore rules from your dependencies's
                        Snyk policies, otherwise ignore policies are only
                        shown as a suggestion.
+  --show-vulnerable-paths=<boolean>
+                       Display the dependency paths from the top level
+                       dependencies, down to the vulnerable packages (defaults
+                       to true). Applicable to `snyk test`.
   --dry-run .......... Don't apply updates or patches during protect.
   -q, --quiet ........ Silence all output.
   -h, --help ......... This help information.
@@ -42,6 +46,7 @@ Examples:
   $ snyk test
   $ snyk test ionic@1.6.5
   $ snyk monitor --org=my-team
+  $ snyk test --show-vulnerable-paths=false
 
 Pro tip: use `snyk test` in your test scripts, if a vulnerability is
 found, the process will exit with a non-zero exit code.