Fix KB/MB bug, use Telemetry

Issue #260.

Author: AlexDaniel

lib/Whateverable.pm6

@@ -157,8 +157,9 @@ multi method irc-to-me(Message $msg where .text ~~ /:i^ help ‘?’? $/) {
 }
 multi method irc-to-me(Message $msg where .text ~~ /:i^ uptime $/) {
     use nqp;
+    use Telemetry;
     (denominate now - INIT now) ~ ‘, ’
-    ~ nqp::atpos_i(nqp::getrusage(), nqp::const::RUSAGE_MAXRSS).fmt(‘%.2f’)/1000 ~ ‘KB maxrss. ’
+    ~ T<max-rss>.fmt(‘%.2f’) ÷ 1000 ~ ‘MB maxrss. ’
     ~ (with nqp::getcomp("perl6") {
         “This is {.implementation} version {.config<version>} ”
         ~ “built on {.backend.version_string} ”