docs(MIGRATION) Note vcspull sync completion update

Author: tony

MIGRATION

@@ -25,9 +25,27 @@ _Notes on the upcoming release will be added here_
 
 <!-- Maintainers, insert changes / features for the next release here -->
 
+## vcspull 1.15.4 (unreleased)
+
+### Completions for `-c` / `--config` files
+
+_via #403_
+
+After updating, you can re-run [shtab]'s setup (see [completions page]) completion of:
+
+```console
+$ vcspull sync -c [tab]
+```
+
+```console
+$ vcspull sync --config [tab]
+```
+
 ## vcspull 1.15.0 (2022-10-09)
 
-### Completions have changed (#400)
+### Completions have changed
+
+_via #400_
 
 Completions now use a different tool: [shtab]. See the [completions page] for more information.
 
@@ -40,6 +58,8 @@ If you were using earlier versions of vcspull (earlier than 1.15.0), you may nee
 
 ### Pulling all repositories
 
+_via #394_
+
 Empty command will now show help output
 
 ```console
@@ -65,6 +85,8 @@ Depending on how shell escaping works in your shell setup with [wild card / aste
 
 ### Terms with no match in config will show a notice
 
+_via #394_
+
 > No repo found in config(s) for "non_existent_repo"
 
 - Syncing will now skip to the next repos if an error is encountered
@@ -85,8 +107,10 @@ $ vcspull --log-level DEBUG sync --exit-on-error grako django
 
 ### Untracked files
 
+_via https://github.com/vcs-python/libvcs/pull/425_
+
 Syncing in git repositories with untracked files has been improved (via libvcs
-0.17, https://github.com/vcs-python/libvcs/pull/425)
+0.17)
 
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