issue alert config fixes (#4655)

Author: imatwawana

src/docs/product/alerts/create-alerts/issue-alert-config.mdx

@@ -28,7 +28,7 @@ Give your alert a descriptive name, such as the team affected and the topic of t
 
 "When" conditions, or triggers, specify what type of activity you'd like monitored for the issue:
 
-- First seen
+- New issue is created
 - Changes state from `resolved` to `unresolved`
 - Changes state from `ignored` to `unresolved`
 - The number of events in an issue is more than a certain number or has a higher [percent change](#change-alerts) in an interval
@@ -57,15 +57,9 @@ For example, an alert can be triggered when an issue is affecting 10% more uniqu
 
 You can set a trigger for when an issue affects more than {X} percent of [sessions](/product/releases/health/#session) in {time}.
 
-This is approximated by taking the number of sessions in the last hour and scaling it to the alerting window appropriately. For example, if the alert is configured to look at the last 5 minutes, the number of sessions is approximated by taking the number of sessions in the last hour and dividing it by 12.
+_Percent of sessions affected_ is an approximation that's calculated by taking the number of sessions in the last hour and scaling it to the alerting window appropriately. For example, if the alert is configured to look at the last five minutes, the number of sessions is approximated by taking the number of sessions in the last hour and dividing it by 12.
 
-<Note>
-
-_Percent of sessions affected_ is an approximation, calculated as the ratio of the issue’s frequency to the number of sessions in the project.
-
-</Note>
-
-Also, percent-based alerts will only trigger if the number of sessions in the last hour exceeds 50.
+Percent-based alerts will only trigger if the number of sessions in the last hour exceeds 50.
 
 ## "If" Conditions: Filters