Add missing 'RGRAPHIC' command to '11.PARSE'

[gurcei]

As experienced by TommyROM in discord:

• https://discord.com/channels/719326990221574164/805252939593416705/1065136317056417823

Using RGRAPHIC presently results in an error, as the parser isn't looking for it.

Should be a straightforward fix

[gurcei]

@rscottfree recently repaired this in this PR: https://github.com/MEGA65/eleven/pull/3