docs: add supported SMS/voice countries to docs #2080

Job	Run time
Linting and tests / Lint entire project	1m 14s
Linting and tests / Lint, test, and build frontend	1m 35s
Linting and tests / Test technical documentation	24s
Linting and tests / Lint database migrations	1m 10s
Linting and tests / Backend Tests: MySQL + RabbitMQ (RBAC enabled: True)	4m 14s
Linting and tests / Backend Tests: Plugin	31s
Linting and tests / Backend Tests: MySQL + RabbitMQ (RBAC enabled: False)	4m 9s
Linting and tests / Helm Chart Unit Tests	18s
Linting and tests / Backend Tests: PostgreSQL + RabbitMQ (RBAC enabled: True)	3m 48s
Linting and tests / Backend Tests: SQLite + Redis (RBAC enabled: True)	3m 22s
Linting and tests / Unit tests - Migrators	20s
Linting and tests / Backend Tests: PostgreSQL + RabbitMQ (RBAC enabled: False)	3m 54s
Linting and tests / Backend Tests: SQLite + Redis (RBAC enabled: False)	3m 22s
Linting and tests / mypy	1m 27s
Snyk security scan / Snyk security scan	1m 14s
Linting and tests / Standard e2e tests (10.3.0) / Grafana: 10.3.0	7m 58s
Linting and tests / Standard e2e tests (11.2.0) / Grafana: 11.2.0	7m 50s
	46m 50s

Provide feedback