Possible impact due to planned removal of Babel from jsqubits build

[davidbkemp]

Hopefully the impact will be minor, but I plan to simplify jsqubits by removing the use of Babel. I have left it using ES modules instead of CommonJS modules.
If there are concerns about the impact on jsqubits.d.ts then please look at the PR and leave comments. I don’t plan to merge the PR for a few days.

davidbkemp/jsqubits#30

[kamakiri01]

Thank you for this issue, I saw your PR.
I have read your PR and will write a comment now. 👀