Fix misspelling of Primitive in documentation

[zacharytamas]

In the type documentation for the form field of the Options, Primitive was misspelled as Primitve. I have corrected this.

Checklist

• I have read the documentation.
• I have included a pull request description of my changes.
• I have included some tests.
• If it's a new feature, I have included documentation updates in both the README and the types.