add information on temporal clustering fields

Author: apigott

config/schema.default.json

@@ -616,7 +616,7 @@
           }
         },
         "temporal": {
-          "description": "Configuration for `clustering.temporal` settings.",
+          "description": "Configuration for `clustering.temporal` settings. Follows the convention of {n}{unit}, e.g. 3H to aggregate over 3 hours time periods. `SEG` can be used to create n segments of varying time periods based on network similarities during those time periods.",
           "properties": {
             "resolution_elec": {
               "anyOf": [