Allow toggleForced to force false

[jcuenod]

Fixes #134

I took a quick look for other similar issues, but I didn't see any. Admittedly, I didn't look particularly carefully, though.

[TheSpyder]

Looks correct! Two things to fix; I need to add a contribution guide at some point 😂

• there is a test that needs updating. The tests don't run any code, they are just there to check the API and code generation. Please make sure to test both true and false.
• please add a changelog entry 👍

[jcuenod]

@TheSpyder let me know if those commits are need any revision.

[TheSpyder]

looks good 👍 maybe one or two things I'd tweak but I can do that myself later.

[jcuenod]

Ping me when you do. This came up in the first project I've used rescript in, so I'd be pleased to learn more idiomatic approaches.