move hook maturity definition requirement

from Hook Maturity section, to Changes to a Hook.
Rename "Changes to the Definition of a Hook (Hook Versioning)" to "Changes to a Hook" to incorporate hook maturity

Author: isaacvetter

docs/specification/1.0.md

@@ -873,7 +873,7 @@ Hook creators SHOULD include examples of the context.
 If the context contains FHIR data, hook creators SHOULD include examples across multiple versions of FHIR if differences across FHIR versions are possible.
 
 ### Hook Maturity Model
-The intent of the CDS Hooks Maturity Model is to attain broad community engagement and consensus, before a hook is labeled as mature, that the hook is necessary, implementable, and worthwhile to the CDS services and CDS clients that would reasonably be expected to use it. Implementer feedback should drive the maturity of new hooks. Diverse participation in open developer forums and events, such as HL7 FHIR Connectathons, is necessary to achieve significant implementer feedback. The below criteria will be evaluated with these goals in mind. The hook definition defines the hook's current maturity level and MUST link to the definition of that maturity level.
+The intent of the CDS Hooks Maturity Model is to attain broad community engagement and consensus, before a hook is labeled as mature, that the hook is necessary, implementable, and worthwhile to the CDS services and CDS clients that would reasonably be expected to use it. Implementer feedback should drive the maturity of new hooks. Diverse participation in open developer forums and events, such as HL7 FHIR Connectathons, is necessary to achieve significant implementer feedback. The below criteria will be evaluated with these goals in mind. 
 
     Hook maturity | 3 - Considered
 
@@ -890,7 +890,7 @@ Maturity Level | Maturity title | Requirements
 6 | Normative | _The above, and ..._ the responsible HL7 working group and the CDS working group agree the material is ready to lock down and the hook has passed HL7 normative ballot
 
 
-### Changes to the Definition of a Hook (Hook Versioning)
+### Changes to a Hook
 
 Each hook MUST include a Metadata table at the beginning of the hook with the specification version and hook version as described in the following sections.
 
@@ -932,9 +932,14 @@ When a major change is made, the hook definition MUST be published under a new n
 
 > Note that the intent of this table is to outline possible breaking changes. The authors have attempted to enumerate these types of changes exhaustively, but as new types of breaking changes are identified, this list will be updated.
 
+#### Hook Maturity
+As each hook progresses through a process of being defined, tested, implemented, used in production environments and balloted, the hook's formal [maturity level](#hook-maturity-model) increases. Each hook has its own maturity level, which MUST be defined in the hook's definition and correspond to the [Hook Maturity Model](#hook-maturity-model). 
+
+    hookMaturity | [0 - Draft](#hook-maturity-model)
+
 #### Change Log
 
-Changes made to a hook MUST be documented in a change log to ensure hook consumers can track what has been changed over the life of a hook. The change log MUST contain the following elements:
+Changes made to a hook's definition MUST be documented in a change log to ensure hook consumers can track what has been changed over the life of a hook. The change log MUST contain the following elements:
 
 - Version: The version of the change
 - Description: A description of the change and its impact