Add documentation clarification (#3382)

* Update how hosts and ports are configured
* Add that monitors cannot be run headful

(cherry picked from commit 3271331)

docs/en/observability/synthetics-configuration.asciidoc

@@ -77,6 +77,11 @@ Read more in <<synthetics-params-secrets>>.
 
 For all available options, refer to the https://playwright.dev/docs/test-configuration[Playwright documentation].
 
+[NOTE]
+====
+Do not attempt to run in headful mode (using `headless:false`) when running through Elastic's global managed testing infrastructure or Private Locations as this is not supported.
+====
+
 Below are details on a few Playwright options that are particularly relevant to Elastic Synthetics including timeouts, timezones, and device emulation.
 
 [discrete]

docs/en/observability/synthetics-create-test.asciidoc

@@ -167,6 +167,11 @@ user workflows including tasks like:
 
 Visit the https://playwright.dev/docs[Playwright documentation] for information.
 
+[NOTE]
+====
+Do not attempt to run in headful mode (using `headless:false`) when running through Elastic's global managed testing infrastructure or Private Locations as this is not supported.
+====
+
 However, not all Playwright functionality should be used with Elastic Synthetics.
 
 In some cases, there are alternatives to Playwright functionality built into the

docs/en/observability/synthetics-reference/lightweight-config/http.asciidoc

@@ -6,8 +6,8 @@
 
 // hosts
 | [[monitor-http-hosts]] *`hosts`*
-(list of <<synthetics-lightweight-data-string,string>>s)
-a| *Required*. A list of URLs to ping.
+(<<synthetics-lightweight-data-string,string>>)
+a| *Required*. The URL to ping.
 
 ////////////////////////
 max_redirects
@@ -70,7 +70,7 @@ a| The TLS/SSL connection settings for use with the HTTPS endpoint. If you don't
 - type: http
   id: my-http-service
   name: My HTTP Service
-  hosts: ["https://myhost:443"]
+  hosts: "https://myhost:443"
   schedule: '@every 5s'
   ssl:
     certificate_authorities: ['/etc/ca.crt']

docs/en/observability/synthetics-reference/lightweight-config/icmp.asciidoc

@@ -6,14 +6,14 @@
 
 // hosts
 | [[monitor-icmp-hosts]] *`hosts`*
-(list of <<synthetics-lightweight-data-string,string>>s)
-a| *Required*. A list of hosts to ping.
+(<<synthetics-lightweight-data-string,string>>)
+a| *Required*. The host to ping.
 
 *Example*:
 
 [source,yaml]
 ----
-hosts: ["myhost"]
+hosts: "myhost"
 ----
 
 ////////////////////////

docs/en/observability/synthetics-reference/lightweight-config/tcp.asciidoc

@@ -6,50 +6,27 @@
 
 // hosts
 | [[monitor-tcp-hosts]] *`hosts`*
-(list of <<synthetics-lightweight-data-string,string>>s)
-a| *Required*. A list of hosts to ping. The entries in the list can be:
-
-* *A plain host name, such as `localhost`, or an IP address.*
-  If you specify this option, you must also specify a value for <<monitor-tcp-ports,`ports`>>.  If the monitor is {heartbeat-ref}/configuration-ssl.html[configured to use SSL], Synthetics establishes an SSL/TLS-based connection. Otherwise, it establishes a plain TCP connection.
+(<<synthetics-lightweight-data-string,string>>)
+a| *Required*. The host to ping. The value can be:
 
 * *A hostname and port, such as `localhost:12345`.*
   Synthetics connects to the port on the specified host. If the monitor is {heartbeat-ref}/configuration-ssl.html[configured to use SSL], Synthetics establishes an SSL/TLS-based connection. Otherwise, it establishes a TCP connection.
 
 * *A full URL using the syntax `scheme://<host>:[port]`*, where:
 ** `scheme` is one of `tcp`, `plain`, `ssl` or `tls`. If `tcp` or `plain` is specified, Synthetics establishes a TCP connection even if the monitor is configured to use SSL. If `tls` or `ssl` is specified, Synthetics establishes an SSL connection. However, if the monitor is not configured to use SSL, the system defaults are used (currently not supported on Windows).
 ** `host` is the hostname.
-** `port` is the port number. If `port` is missing in the URL, the <<monitor-tcp-ports,`ports`>> setting is required.
+** `port` is the port number.
 
 *Examples*:
 
 [source,yaml]
 ----
-hosts: ["localhost"]
-----
-
-[source,yaml]
-----
-hosts: ["localhost:8000"]
-----
-
-[source,yaml]
-----
-hosts: ["tcp://localhost:8000"]
+hosts: "localhost:8000"
 ----
 
-////////////////
-ports
-////////////////
-| [[monitor-tcp-ports]] *`ports`*
-(list of <<synthetics-lightweight-data-string,string>>s)
-a| A list of ports to ping if the host specified in <<monitor-tcp-hosts,`hosts`>> does not contain a port number. It is generally preferable to use a single value here, since each port will be monitored using a separate `id`, with the given `id` value, used as a prefix in the Synthetics data, and the configured `name` shared across events sent via this check.
-
-*Example*:
-
 [source,yaml]
 ----
-hosts: ["localhost"]
-ports: [80, 9200, 5044]
+hosts: "tcp://localhost:8000"
 ----
 
 ////////////////