Merge pull request #4294 from FlowFuse/3818-docs

update docs for snapshot edit

docs/user/envvar.md

@@ -62,3 +62,7 @@ In addition, the following variables are set when running on a device:
 
 When deploying the same set of flows out to multiple devices, these variables can
 be used by the flows to identify the specific device being run on.
+
+NOTE: `FF_SNAPSHOT_NAME` will not be immediately updated when the current snapshot is edited.
+It will only be updated when the snapshot is changed or a setting that causes the device to
+be restarted is changed.

docs/user/snapshots.md

@@ -24,6 +24,20 @@ To create a snapshot:
 
 The list of snapshots will update with the newly created entry at the top.
 
+## Edit a snapshot
+
+To edit a snapshot:
+
+1. Go to the instance's page and select the **Snapshots** tab.
+2. Open the dropdown menu to the right of the snapshot you want to edit and
+   select the **Edit Snapshot** option.
+3. Update the name and description as required.
+4. Click **Update**
+
+NOTE:
+Changes made to a snapshot will not be immediately reflected on devices that are already running this snapshot.
+
+
 ## Download a snapshot
 
 A snapshot can be downloaded to your local machine for backup or sharing.