README.pod: Fix type "In such ca case" => "In such a case" [ci skip]
README.pod: Fix type "In such ca case" => "In such a case" [ci skip]

jddurand/c-marpaESLIF,jddurand/c-marpaESLIF,jddurand/c-marpaESLIF,jddurand/c-marpaESLIF,jddurand/c-marpaESLIF