site/content: regenerate terms

This is based on the new cluster/module re-organization by Peter
last week: idss_schema_fields_new2.xlsx

site/content/terms/global-volume-number/index.md

@@ -0,0 +1,10 @@
+---
+title: 'Volume number'
+field: 'is.extent.volume'
+slug: 'global-volume-number'
+description: 'Journal article volume number'
+required: False
+module: 'Form'
+cluster: 'Global'
+policy: 'Free value. Single value only.'
+---