[DOCS] Replace table of links with single link to Obs alerting docs (#…

…177525)

## Summary

Replaces the categorized table of links with a single link to the
observability alerting docs because this table is likely to get stale
over time (in fact, it already is stale).

The change looks like this when rendered in HTML:


![image](https://github.com/elastic/kibana/assets/14206422/a3f67a18-f227-435d-9b56-ddb221cdce7c)


Notes/open issues:
- [x] The [main alerting
page](https://www.elastic.co/guide/en/kibana/master/alerting-getting-started.html)
for Kibana now has links to related alerting documentation, but is it
clear that those links point to docs that describe how to manage alerts
from those apps? The link text seems maybe not descriptive enough and
might be causing confusion. _NO CHANGE REQUIRED: I'm going to leave this
as-is because I think the feedback we received initially about the lack
of links was before the links were added._
- [x] In the intro, I feel a thought might be missing from this
statement: "For information on creating security rules, refer to Create
a detection rule." Should this instead say something like: "Security
rules must be defined in the Security app. For more information, refer
to the security docs about creating a detection rule." _RESOLVED_
- [x] I think the descriptions about each app's alerting capabilities
should be more consistent, but I don't want to rewrite other folk's
sections. So I have aligned my description with the security section,
for better or worse. It's hard to make this info consistent when each
solution/app is doing its own thing with alerting. _DEFERRED: We will
fix inconsistencies later._
- [x] Is it correct to say "create alerts" rather than something like
"trigger alerts" or "generate alerts"? _RESOLVED: Will keep as "create"
for now since the UI is not using "trigger."_

### Checklist

n/a

cc @lcawl Can you help me sort through my list of open issues?

Co-authored-by: Kibana Machine <[email protected]>

docs/user/alerting/rule-types.asciidoc

@@ -39,35 +39,14 @@ see {subscriptions}[the subscription page].
 [[observability-rules]]
 === {observability} rules
 
-{observability} rules are categorized into APM and {user-experience}, Logs, Metrics, {stack-monitor-app}, and Uptime.
+{observability} rules detect complex conditions in your observability data and create alerts when a rule's conditions are met. For example, you can create a rule that detects when the value of a metric exceeds a specified threshold or when an anomaly occurs on a system or service you are monitoring. For more information, refer to {observability-guide}/create-alerts.html[Alerting].
 
 [NOTE]
 ==============================================
 If you create a rule in the {observability} app, its alerts are not visible in
 *{stack-manage-app} > {rules-ui}*. They are visible only in the {observability} app.
 ==============================================
 
-[cols="2*<"]
-|===
-
-
-| <<apm-alerts, APM and User Experience>>
-| Detect complex conditions in *APM* data and trigger built-in actions when the conditions are met.
-
-| {observability-guide}/logs-threshold-alert.html[Logs rules]
-| Detect complex conditions in the {logs-app}.
-
-| {observability-guide}/metrics-threshold-alert.html[Metrics rules]
-| Detect complex conditions in the {metrics-app}.
-
-| {observability-guide}/slo-burn-rate-alert.html[SLO burn rate rule]
-| Detect when the burn rate is above a defined threshold.
-
-| {observability-guide}/monitor-status-alert.html[Uptime rules]
-| Detect complex conditions in the {uptime-app}.
-
-|===
-
 [float]
 [[ml-rules]]
 === Machine learning rules