Supplement docs for db setup with email tags

README.md

@@ -1,7 +1,9 @@
-# Expert bot to lookup contact information in a database
+# Two expert bots to lookup contact information in a database and apply notification rules
 
 Part of the [intelmq-cb-mailgen solution](https://github.com/Intevation/intelmq-mailgen-release).
 
+An overview of the setup can be gained from the [IntelMQ Mailgen Docs](https://github.com/Intevation/intelmq-mailgen/tree/master/docs).
+
 ## Contact DB
 
 ### Automatic versus manual contacts
@@ -129,6 +131,34 @@ configuration for accessing the database.
 
 ```
 
+#### Adding default email tags
+
+The names, values and default values for tags directly associated with
+an email address have to be saved in the database.
+(Maybe future version of fody-backend and fody will allow editing them, but
+as of 2021-02-25 they don't.)
+
+The following example adds two tag names with a few values:
+
+```sql
+INSERT INTO tag_name (tag_name, tag_name_order) VALUES ('Format', 1);
+# -> id 1
+INSERT INTO tag_name (tag_name, tag_name_order) VALUES ('Constituency', 2);
+# -> id 2
+
+COPY tag (tag_name_id, tag_value, tag_description, is_default) FROM STDIN;
+1	CSV_inline	CSV inline	true
+1	CSV_attachment	CSV attachment	false
+2	network_operators	Network Operators	true
+2	government	Government	false
+2	CNI	Critical National Infrastructure	false
+2	CNI_energy	CNI Energy	false
+\.
+```
+
+(Tags for emails have been added with release 0.9.4 in 2019-05.)
+
+
 ### Schema Updates
 
 When upgrading to new version take a look at