Add link to Terminology from req's Definitions

Signed-off-by: Mark Lodato <lodato@google.com>

docs/_spec/v0.1/requirements.md

@@ -67,6 +67,9 @@ _○ = required unless there is a justification_
 
 ## Definitions
 
+> See also [Terminology](terminology.md) for general SLSA concepts. The
+> defintions below are only used in this document.
+
 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD",
 "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be
 interpreted as described in [RFC 2119](https://www.rfc-editor.org/rfc/rfc2119).