Merge pull request 'docs: get list of keycloak users' email addresses' (#15) from add-docs-keycloak-email into main

Reviewed-on: pub-solar/infra#15
Reviewed-by: b12f <hello@benjaminbaedorf.eu>

docs/keycloak-email-list.md

@@ -0,0 +1,22 @@
+# Process for getting a list of email addresses of all keycloak users
+
+### Keycloak
+Required:
+- auth.pub.solar ops user credentials
+- SSH access to host flora-6
+```
+ssh barkeeper@flora-6.pub.solar
+
+sudo --user keycloak kcadm.sh get users \
+  -r pub.solar \
+  --offset 0 \
+  --limit 1000 \
+  --no-config \
+  --server http://localhost:8080 \
+  --realm master \
+  --user admin \
+  --password <admin password> \
+  > keycloak-user-list.json
+
+jq -r '.[].email' < keycloak-user-list.json
+```