Added note about suffixing theme IDs with '-theme' for clarity. As discussed in https://github.com/zed-industries/extensions/pull/4693#pullrequestreview-3751636461 - [ ] ~Tests or screenshots needed?~ - [x] Code Reviewed - [ ] ~Manual QA~ Release Notes: - Clarified theme ID suffixing in extension docs --------- Co-authored-by: Finn Evers <finn.evers@outlook.de>