Fix typo in the HCL spec

[amirhosseinab]

Change schemata to schema

[hashicorp-cla-app]

All committers have signed the CLA.

[crw]

Thanks for your submission! I believe the author was intentionally using schemata as the plural form of schema. This usage appears to be correct if uncommon. I suspect this would not fit in with HashiCorp's style guide today, but it is unclear if this document would be subject to that style guide. Which is a long-winded way of saying, this may or may not be accepted but thanks for pointing it out!

[apparentlymart]

This text originated in the spec from ZCL, which was my personal project that HashiCorp later adopted as HCL 2, so I'm afraid this text is my fault.

@crw is right that this was intended to be the plural of "schema", because it's describing the potentially-many things that can appear inside a singular "body schema". If I'd written this in the "HashiCorp writing voice" then I expect each of the modifications made here would say "schemas" (plural) instead of either "schemata" or "schema", and I'd think that a reasonable change to accept here but of course that's not my call to make. 😀