Add support for the mdbook-svgbob plugin

[jontze]

Implement the mdbook-svgbob plugin to the supported plugins of this action.

Advantages:

• mdbook-svgbob doesn't have a stable github release (only a pre-release)
• Pre-releases are currently not supported by this action
• Missing github release with attached binaries for v0.2.0 Missing git tag for v0.2.0 boozook/mdbook-svgbob#20

Blocked by

• Allow the optional use of pre-releases #299
• A stable release mdbook-svgbob with pre-compiled binaries attached. This should be possible after the implementation of: Refactor release pipeline boozook/mdbook-svgbob#21

Came up during #211