revert for "election_id"

Author: Mr-Leshiy

docs/src/architecture/08_concepts/signed_doc/cddl/additional_meta.cddl

@@ -7,7 +7,7 @@ additional_fields = {
   ? "collabs" => [+any],
   ? "brand_id" => ref_type,
   ? "campaign_id" => ref_type,
-  ? "election_id" => ref_type,
+  ? "election_id" => UUID, ; UUID v4
   ? "category_id" => ref_type,
 }
 

docs/src/architecture/08_concepts/signed_doc/meta.md

@@ -95,11 +95,8 @@ The format is the same as the [CBOR] Array form of [`ref`](#ref-document-referen
 
 ## `campaign_id`
 
-This is a reply to another document.
-The format is the same as the [CBOR] Array form of [`ref`](#ref-document-reference).
-
-`campaign_id` defines a "campaign" of voting, e.g. "treasury campaign".
-
+Unique identifier [UUID] v4, which defines an election,
+e.g. "Catalyst Fund 1", "Catalyst Fund 2".
 
 ## `election_id`