Standardize doc page title handling

See https://groups.google.com/g/prometheus-developers/c/cwL3cM66Em8

Signed-off-by: Julius Volz <julius.volz@gmail.com>

docs/alertmanager.md

@@ -4,8 +4,6 @@ sort_rank: 2
 nav_icon: sliders
 ---
 
-# Alertmanager
-
 The [Alertmanager](https://github.com/prometheus/alertmanager) handles alerts
 sent by client applications such as the Prometheus server.
 It takes care of deduplicating, grouping, and routing

docs/alerts_api.md

@@ -10,8 +10,6 @@ series data instead of sending alerts to the Alerts API, as Prometheus supports
 a number of special cases to make sure alerts are delivered even if Alertmanager
 crashes or restarts.
 
-# Alerts API
-
 You send alerts to Alertmanager via APIv2. The APIv2 is specified as an
 OpenAPI specification that can be found [here](https://github.com/prometheus/alertmanager/blob/master/api/v2/openapi.yaml).
 
@@ -75,4 +73,4 @@ To ensure resolved notifications are sent for resolved alerts, clients are also
 expected to re-send resolved alerts to the Alertmanager for up to 5 minutes
 after the alert has resolved. As the Alertmanager is stateless, this ensures
 that a resolved notification is sent even if the Alertmanager crashes or is
-restarted.
+restarted.

docs/configuration.md

@@ -4,8 +4,6 @@ sort_rank: 3
 nav_icon: sliders
 ---
 
-# Configuration
-
 [Alertmanager](https://github.com/prometheus/alertmanager) is configured via
 command-line flags and a configuration file.
 While the command-line flags configure immutable system parameters, the

docs/https.md

@@ -3,8 +3,6 @@ title: HTTPS and authentication
 sort_rank: 11
 ---
 
-# HTTPS and authentication
-
 Alertmanager supports basic authentication and TLS.
 This is **experimental** and might change in the future.
 
@@ -158,15 +156,15 @@ tls_server_config:
 tls_client_config:
   # Path to the CA certificate with which to validate the server certificate.
   [ ca_file: <filepath> ]
-    
+
   # Certificate and key files for client cert authentication to the server.
   [ cert_file: <filepath> ]
   [ key_file: <filepath> ]
-  
+
   # Server name extension to indicate the name of the server.
   # http://tools.ietf.org/html/rfc4366#section-3.1
   [ server_name: <string> ]
-  
+
   # Disable validation of the server certificate.
   [ insecure_skip_verify: <boolean> | default = false]
 ```

docs/management_api.md

@@ -3,8 +3,6 @@ title: Management API
 sort_rank: 9
 ---
 
-# Management API
-
 Alertmanager provides a set of management API to ease automation and integrations.
 
 

docs/notification_examples.md

@@ -2,7 +2,6 @@
 title: Notification template examples
 sort_rank: 8
 ---
-# Notification Template Examples
 
 The following are all different examples of alerts and corresponding Alertmanager configuration file setups (alertmanager.yml).
 Each use the [Go templating](http://golang.org/pkg/text/template/) system.

docs/notifications.md

@@ -2,7 +2,6 @@
 title: Notification template reference
 sort_rank: 7
 ---
-# Notification Template Reference
 
 Prometheus creates and sends alerts to the Alertmanager which then sends notifications out to different receivers based on their labels.
 A receiver can be one of many integrations including: Slack, PagerDuty, email, or a custom integration via the generic webhook interface.

docs/overview.md

@@ -4,8 +4,6 @@ sort_rank: 1
 nav_icon: sliders
 ---
 
-# Alerting Overview
-
 Alerting with Prometheus is separated into two parts. Alerting rules in
 Prometheus servers send alerts to an Alertmanager. The [Alertmanager](alertmanager.md)
 then manages those alerts, including silencing, inhibition, aggregation and