feat(0004): clarify resource names requirements

A requirement stated that only alphanumerics were allowed,
conflicting with a line later that also allowed kebab-cased 
dashes.

Clarifying that dashes are indeed allowed.

fixes #396

Author: toumorokoshi

aep/general/0004/aep.md.j2

@@ -24,7 +24,7 @@ indicated by it's namespacing within the API name.
 
 The type name:
 
-- **must** only contain ASCII alphanumeric characters.
+- **must** only contain ASCII alphanumeric characters and dashes (`-`).
 - **must** start with a lowercase letter.
 - **must** be of the singular form of the resource.
 - **must** use kebab case.