docs: update obslog description

cli/src/commands/obslog.rs

@@ -28,9 +28,10 @@ use crate::formatter::Formatter;
 use crate::graphlog::{get_graphlog, Edge};
 use crate::ui::Ui;
 
-/// Show how a change has evolved
+/// Show how a change has evolved over time
 ///
-/// Show how a change has evolved as it's been updated, rebased, etc.
+/// Lists the previous commits which a change has pointed to. The current commit
+/// of a change evolves when the change is updated, rebased, etc.
 ///
 /// Name is derived from Merciual's obsolescence markers.
 #[derive(clap::Args, Clone, Debug)]

cli/tests/cli-reference@.md.snap

@@ -125,7 +125,7 @@ To get started, see the tutorial at https://github.com/martinvonz/jj/blob/main/d
 * `move` — Move changes from one revision into another
 * `new` — Create a new, empty change and (by default) edit it in the working copy
 * `next` — Move the working-copy commit to the child revision
-* `obslog` — Show how a change has evolved
+* `obslog` — Show revisions of the same Change-Id
 * `operation` — Commands for working with the operation log
 * `parallelize` — Parallelize revisions by making them siblings
 * `prev` — Change the working copy revision relative to the parent revision
@@ -1204,7 +1204,7 @@ implied.
 
 ## `jj obslog`
 
-Show how a change has evolved
+Show revisions of the same Change-Id
 
 Show how a change has evolved as it's been updated, rebased, etc.