* fix(types): type `LoadedPlugin` is not generic
`LoadedPlugin` referenced line 201 is not generic, causing typescript errors on
end-user builds.
* chore(types): add typescript dev dep, tsconfig and a test script
Contributors will no longer inadvertently dump type errors since any IDE should
check types now.
* add missing plugins generic types
Co-authored-by: slorber <lorber.sebastien@gmail.com>
Jules Sam. Randolph