[Docs]: some equinix_fabric_connection using deprecated equinix_ecx_l2_connection fields

[ocobles]

I found at least three examples using resource equinix_fabric_connection that replaced equinix_ecx_l2_connection but without updating the fields, so now most of those fields are different

terraform-provider-equinix/examples/resources/equinix_metal_connection/shared_no_token_metal_to_fabric.tf

Lines 28 to 36 in f303197

	resource "equinix_fabric_connection" "example" {
	name = "tf-port-to-metal-legacy"
	speed = "200"
	speed_unit = "MB"
	notifications = ["example@equinix.com"]
	port_uuid = data.equinix_fabric_port.example.id
	vlan_stag = 1020
	authorization_key = equinix_metal_connection.example.token
	}

terraform-provider-equinix/examples/resources/equinix_metal_connection/shared_token_fabric_port_to_metal.tf

Lines 24 to 32 in f303197

	resource "equinix_fabric_connection" "example" {
	name = "tf-port-to-metal"
	zside_service_token = equinix_metal_connection.example.service_tokens.0.id
	speed = "200"
	speed_unit = "MB"
	notifications = ["example@equinix.com"]
	port_uuid = data.equinix_fabric_port.example.id
	vlan_stag = 1020
	}

terraform-provider-equinix/examples/resources/equinix_metal_connection/shared_token_metal_to_csp.tf

Lines 17 to 31 in f303197

	resource "equinix_fabric_connection" "example" {
	name = "tf-metal-to-azure"
	profile_uuid = data.equinix_fabric_sellerprofile.example.uuid
	speed = azurerm_express_route_circuit.example.bandwidth_in_mbps
	speed_unit = "MB"
	notifications = ["example@equinix.com"]
	service_token = equinix_metal_connection.example.service_tokens.0.id
	seller_metro_code = "AM"
	authorization_key = azurerm_express_route_circuit.example.service_key
	named_tag = "PRIVATE"
	secondary_connection {
	name = "tf-metal-to-azure-sec"
	service_token = equinix_metal_connection.example.service_tokens.1.id
	}
	}