Improve formatting of push.md

Signed-off-by: Kim Brose <2803622+HarHarLinks@users.noreply.github.com>

changelogs/internal/newsfragments/1415.clarification

@@ -0,0 +1 @@
+Improve formatting of push.md

content/client-server-api/modules/push.md

@@ -50,31 +50,31 @@ such as Apple's APNS or Google's GCM. This happens as follows:
 
 Definitions for terms used in this section are below:
 
-Push Provider
+**Push Provider**:
 A push provider is a service managed by the device vendor which can send
 notifications directly to the device. Google Cloud Messaging (GCM) and
 Apple Push Notification Service (APNS) are two examples of push
 providers.
 
-Push Gateway
+**Push Gateway**:
 A push gateway is a server that receives HTTP event notifications from
 homeservers and passes them on to a different protocol such as APNS for
 iOS devices or GCM for Android devices. Clients inform the homeserver
 which Push Gateway to send notifications to when it sets up a Pusher.
 
-Pusher
+**Pusher**:
 A pusher is a worker on the homeserver that manages the sending of HTTP
 notifications for a user. A user can have multiple pushers: one per
 device.
 
-Push Rule
+**Push Rule**:
 A push rule is a single rule that states under what *conditions* an
 event should be passed onto a push gateway and *how* the notification
 should be presented. These rules are stored on the user's homeserver.
 They are manually configured by the user, who can create and view them
 via the Client/Server API.
 
-Push Ruleset
+**Push Ruleset**:
 A push ruleset *scopes a set of rules according to some criteria*. For
 example, some rules may only be applied for messages from a particular
 sender, a particular room, or by default. The push ruleset contains the