Bump showdown in the npm_and_yarn group across 1 directory

Bumps the npm_and_yarn group with 1 update in the / directory: [showdown](https://github.com/showdownjs/showdown).


Removes `showdown`

---
updated-dependencies:
- dependency-name: showdown
  dependency-version:
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]