Update docs

example/paper.md

@@ -420,27 +420,50 @@ roles.
 13. [writing-original-draft](https://credit.niso.org/contributor-roles/writing-original-draft)
 14. [writing-review-editing](https://credit.niso.org/contributor-roles/writing-review-editing)
 
-For example, this can be used to identify which authors materially contributed to the paper,
+JATS also specifies three degrees which can be used to quantify the impact of a contribution:
+
+1. `Lead`
+2. `Supporting`
+3. `Equal` - for use if multiple equivalent leads
+
+Together, these can be used to identify which authors materially contributed to the paper,
 such as through `formal-analysis` or `data-curation` and which authors contributed immaterially,
-such as through `supervision`.
+such as through `supervision`. It also allows for saying if multiple people made the same
+kind of contribution, who took the lead.
 
 ```yaml
 authors:
   - name: John Doe
     affiliation: [ 1 ]
     roles:
       - type: 'formal-analysis'
+        degree: 'lead'
 
   - name: John Boss
     affiliation: [ 1 ]
     roles:
       - type: 'funding-acquisition'
+        degree: 'lead'
       - type: 'supervision'
+        degree: 'lead'
 ```
 
-> **Why use a dictionary?**
-> It might be valuable to extend role annotations in the future with qualifiers
-> for impact such as `major` or `minor`, or something else entirely.
+Roles are optional, and within roles, degrees are optional. It's possible to shorthand
+roles by using strings directly:
+
+```yaml
+authors:
+  - name: John Doe
+    affiliation: [ 1 ]
+    roles:
+      - 'formal-analysis'
+
+  - name: John Boss
+    affiliation: [ 1 ]
+    roles:
+      - 'funding-acquisition'
+      - 'supervision'
+```
 
 # Internal references