Failure to generate typedocs

[lholmquist]

Describe the Bug
Running the npm run generate-docs command fails.

Steps to Reproduce

1. npm install
2. npm run gerenate-docs

Expected Behavior
It should generate docs

Additional context
There was an update recently from typedoc@0.18.x to typedocs@0.20.x, which according to the release notes, does have some breaking changes, https://github.com/TypeStrong/typedoc/releases/tag/v0.20.0