Code syntax not rendered in certain cases

[st0012]

Given this code from Ruby's doc/syntax/calling_methods.rdoc:

The <code>**</code> unpacking operator can be applied to any object, not only
hashes. If the object responds to a <code>#to_hash</code> method, this method
is called, and is expected to return an Hash, and elements of this hash are passed
as keyword arguments:

The #to_hash is not rendered as inline code while it should be:

[st0012]

Already addressed by #1676