Add further check to MS2

Add check for availability of metadata.json to MS2 check

.github/PULL_REQUEST_TEMPLATE.md

@@ -24,6 +24,7 @@ Closes #
 - [ ] **use constraints** to make known constraints from the use case explicit in the aspect model 
 - [ ] when relying on **external standards**, they are referenced through a **"see"** element
 - [ ] all properties with an [simple type](https://openmanufacturingplatform.github.io/sds-documentation/bamm-specification/v1.0.0/datatypes.html) have an example value
+- [ ] metadata.json exists with status "release"
 
 ## MS3 Criteria
 (to be filled out by semantic modeling team before merge to main-branch)
@@ -32,4 +33,4 @@ Closes #
 - [ ] The new aspect (version) will be consumed by at least one data consumer
 - [ ] There exists valid test data
 - [ ] In case of a new (incompatible) major version to an existing version, a migration strategy has been developed
-- [ ] The model has at least version '1.0.0'
+- [ ] The model has at least version '1.0.0'