Add "Delimiter" entry

Useful when talking about templating languages, like EJS, used often in various backend software for text-based variable replacement.

A definition could be:
> a character or sequence of characters used to define boundaries between separate data fields or text segments.

Add a “Delimiter” entry to the SJSJ jargon glossary, using the proposed definition and the templating-language context. Review nearby entries to match the project’s format, then verify that the new term and definition appear correctly.

Written by the indexing model from the issue text.