Add “variable” number

Issue #2 resolved
repo owner created an issue

In FWC there are many things allowed where {{{{var}}}} can be used. But while it treats {{{is "abc"}}} like {{{arg is# "abc"}}}, {{{is 10}}} is treated as {{{arg is# s:10}}}. It does make sense to treat this as {{{arg is# 10}}} because in any case adding key {{{10}}} to script-local scope is not allowed.