HPCC-9938 Spelling & Grammar in Documentation

Alters grammar in file docs/ECLLanguageReference/ECLR_mods/Templ-OPTION.xml

Signed-off-by: jamienoss <james.noss@lexisnexis.com>
Merge pull request #4796 from jamienoss/issue9938

HPCC-9938 Spelling & Grammar in Documentation

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>