chore: add language identifiers, remove dead link

link to `#substitution-format` went nowhere, maybe linking this doc would be helpful but I just removed it for now
- https://docs.newrelic.com/docs/alerts-applied-intelligence/notifications/message-templates/#handlebars-syntax

src/content/docs/alerts-applied-intelligence/new-relic-alerts/advanced-alerts/advanced-techniques/alert-custom-incident-descriptions.mdx

@@ -39,9 +39,9 @@ For some [types of conditions](#requirements), you can create a custom incident
 * Define next steps
 * Add metadata to downstream systems
 
-The <DoNotTranslate>**Custom incident description**</DoNotTranslate> field allows you to use a general template structure that, when an incident is generated, [substitutes the generic sections with specific values](#substitution-format). For example, let's say you used this in a description:
+The <DoNotTranslate>**Custom incident description**</DoNotTranslate> field allows you to use a general template structure that, when an incident is generated, substitutes the generic sections with specific values. For example, let's say you used this in a description:
 
-```
+```handlebars
 This is my condition name : {{conditionName}}
 The hostname is : {{tag.fullHostname}}
 ```
@@ -71,8 +71,8 @@ You can create a custom incident description using [the dedicated field for NRQL
 
 Here's a custom incident description template example:
 
-```
-this is my condition name : {{conditionName}}
+```handlebars
+This is my condition name : {{conditionName}}
 The hostname is : {{tag.fullHostname}}
 Owning Team: {{tag.label.owning_team}}
 Product: {{tag.label.product}}
@@ -96,20 +96,20 @@ The attributes you can use in a custom incident description are a subset of attr
 
 * Incident event attributes: For any of the [standard attributes available for use in a custom incident description](/docs/alerts-applied-intelligence/new-relic-alerts/advanced-alerts/understand-technical-concepts/incident-event-attributes), use the format `{{AN_ATTRIBUTE}}`. For example:
 
-  ```
+  ```handlebars
   The target name is : {{targetName}}
   ```
 * Tag attributes: For tags, you would use the format `{{tag.TAG_NAME}}`. There are two types of tags:
 
   * Entity-related tags: <DoNotTranslate>**For infrastructure conditions only.**</DoNotTranslate> You can find available [entity-related tags](/docs/new-relic-one/use-new-relic-one/core-concepts/tagging-use-tags-organize-group-what-you-monitor#) by going to the [entity explorer](/docs/new-relic-one/use-new-relic-one/ui-data/new-relic-one-entity-explorer-view-performance-across-apps-services-hosts) and looking under a service's <DoNotTranslate>**Metadata and tags**</DoNotTranslate>, or by viewing incident details. Here's an example of using tags in a custom incident description:
 
-    ```
+    ```handlebars
     The AWS region is : {{tag.aws.awsRegion}}
     Responsible team : {{tag.label.owning_team}}
     ```
   * Facet clause tags: <DoNotTranslate>**For NRQL conditions only.**</DoNotTranslate> If a NRQL condition uses a `FACET` clause, you can use `tag` formatting to use those values in your custom incident description. For example, if the NRQL query included `FACET hostName, cluster`, you could then use this:
 
-    ```
+    ```handlebars
     The host is : {{tag.hostName}}
     The cluster is : {{tag.cluster}}
     ```
@@ -122,19 +122,27 @@ You can create a custom incident description on a NRQL alert condition through a
 
 Here's an empty mutation template:
 
-```
+```graphql
 mutation {
-  alertsNrqlConditionStaticUpdate(accountId: YOUR_ACCOUNT_ID, id: "YOUR_CONDITION_ID", condition: {description: ""}) {
+  alertsNrqlConditionStaticUpdate(
+    accountId: YOUR_ACCOUNT_ID
+    id: "YOUR_CONDITION_ID"
+    condition: {description: ""}
+  ) {
     YOUR_CUSTOM_INCIDENT_DESCRIPTION
   }
 }
 ```
 
 Here's an example mutation with a custom incident description:
 
-```
+```graphql
 mutation {
-  alertsNrqlConditionStaticUpdate(accountId: 123456, id: "123456", condition: {description: "timestamp : {{timestamp}} \n accountId : {{accountId}} \n type : {{type}} \n event : {{event}} \n description : {{description}} \n policyId : {{policyId}} \n policyName: {{policyName}} \n conditionName : {{conditionName}} \n conditionId : {{conditionId}} \n product : {{product}} \n conditionType : {{conditionType}} \n RunbookUrl : {{runbookUrl}} \n nrqlQuery : {{nrqlQuery}} \n nrqlEventType : {{nrqlEventType}} \n targetID : {{targetId}} \n targetName : {{targetName}} \n commandLine : {{tag.commandLine}} \n entityGuid : {{tag.entityGuid}} \n entityName : {{tag.entityName}} \n fullHostname : {{tag.fullHostname}} \n instanceType : {{tag.instanceType}} \n processDisplayName : {{tag.processDisplayName}}"}) {
+  alertsNrqlConditionStaticUpdate(
+    accountId: 123456
+    id: "123456"
+    condition: {description: "timestamp : {{timestamp}} \n accountId : {{accountId}} \n type : {{type}} \n event : {{event}} \n description : {{description}} \n policyId : {{policyId}} \n policyName: {{policyName}} \n conditionName : {{conditionName}} \n conditionId : {{conditionId}} \n product : {{product}} \n conditionType : {{conditionType}} \n RunbookUrl : {{runbookUrl}} \n nrqlQuery : {{nrqlQuery}} \n nrqlEventType : {{nrqlEventType}} \n targetID : {{targetId}} \n targetName : {{targetName}} \n commandLine : {{tag.commandLine}} \n entityGuid : {{tag.entityGuid}} \n entityName : {{tag.entityName}} \n fullHostname : {{tag.fullHostname}} \n instanceType : {{tag.instanceType}} \n processDisplayName : {{tag.processDisplayName}}"}
+  ) {
     description
   }
 }