order-select to maturity level 4

Per https://confluence.hl7.org/display/CDS/CDS+Hooks+Hook+Maturity?flashId=653343941

Author: isaacvetter

docs/hooks/order-select.md

@@ -4,7 +4,7 @@
 | ---- | ----
 | specificationVersion | 1.0
 | hookVersion | 1.0
-| Hook maturity | [1 - Submitted](../../specification/1.0/#hook-maturity-model)
+| Hook maturity | [4 - Documented](../../specification/1.0/#hook-maturity-model)
 
 ## Workflow