Currently, the parser treats a single title line doc as a simple string and does not try to parse it as a dynamic string:
Runfile
## Doc line in ${.RUNFILE}
line:
echo hello
##
# Doc Block in ${.RUNFILE}
block:
echo hello
testing
$ run list
Commands:
list (builtin) List available commands
help (builtin) Show help for a command
version (builtin) Show run version
line Doc line in ${.RUNFILE}
block Doc Block in /tmp/Runfile
expected
...
line Doc line in /tmp/Runfile
...