Fix docs for VSA lead time calculation

Commits are only associated with issues when they mention an issue
number in the commit message. This removes the documentation that
indicated otherwise.

doc/user/analytics/value_stream_analytics.md

@@ -58,10 +58,7 @@ GitLab provides the ability to filter analytics based on a date range. To filter
 The "Time" metrics near the top of the page are measured as follows:
 
 - **Lead time**: median time from issue created to issue closed.
-- **Cycle time**: median time from first commit to issue closed.
-
-NOTE:
-A commit is associated with an issue by [crosslinking](../project/issues/crosslinking_issues.md) in the commit message or by manually linking the merge request containing the commit.
+- **Cycle time**: median time from first commit to issue closed. (You can associate a commit with an issue by [crosslinking in the commit message](../project/issues/crosslinking_issues.md#from-commit-messages).)
 
 ## How the stages are measured
 

doc/user/group/value_stream_analytics/index.md

@@ -76,9 +76,7 @@ GitLab provides the ability to filter analytics based on a date range. To filter
 The "Time" metrics near the top of the page are measured as follows:
 
 - **Lead time**: median time from issue created to issue closed.
-- **Cycle time**: median time from first commit to issue closed.
-
-A commit is associated with an issue by [crosslinking](../../project/issues/crosslinking_issues.md) in the commit message or by manually linking the merge request containing the commit.
+- **Cycle time**: median time from first commit to issue closed. (You can associate a commit with an issue by [crosslinking in the commit message](../../project/issues/crosslinking_issues.md#from-commit-messages).)
 
 ![Value stream analytics time metrics](img/vsa_time_metrics_v13_0.png "Time metrics for value stream analytics")