Provider name should not allow numbers

[jnv]

This seems to be missing from the internal documentation and I didn't participate in previous discussions, but @zdne confirmed that provider name (identifier) should allow only for lowercase letters and dashes, so this pattern is not correct:

spec/spec/draft/provider-spec.yaml

Lines 4 to 6 in 555d50a

	name:
	type: string
	pattern: "^[a-z][_\\-0-9a-z]*$"

Could you please confirm and check it? Notion page and #29 need to be updated as well.

Just for context, is this intended to lower the risk of typo attacks (e.g. google vs. goog1e)?