Update docs with a few more "path:" repositories references (#635).

docs/how-to/backup-to-a-removable-drive-or-an-intermittent-server.md

@@ -49,9 +49,12 @@ location:
         - /home
 
     repositories:
-        - /mnt/removable/backup.borg
+        - path: /mnt/removable/backup.borg
 ```
 
+<span class="minilink minilink-addedin">Prior to version 1.7.10</span> Omit
+the `path:` portion of the `repositories` list.
+
 Then, write a `before_backup` hook in that same configuration file that uses
 the external `findmnt` utility to see whether the drive is mounted before
 proceeding.
@@ -79,13 +82,16 @@ location:
         - /home
 
     repositories:
-        - ssh://me@buddys-server.org/./backup.borg
+        - path: ssh://me@buddys-server.org/./backup.borg
 
 hooks:
     before_backup:
       - ping -q -c 1 buddys-server.org > /dev/null || exit 75
 ```
 
+<span class="minilink minilink-addedin">Prior to version 1.7.10</span> Omit
+the `path:` portion of the `repositories` list.
+
 Or to only run backups if the battery level is high enough:
 
 ```yaml

docs/how-to/make-backups-redundant.md

@@ -24,6 +24,9 @@ location:
         - path: /var/lib/backups/local.borg
 ```
 
+<span class="minilink minilink-addedin">Prior to version 1.7.10</span> Omit
+the `path:` portion of the `repositories` list.
+
 When you run borgmatic with this configuration, it invokes Borg once for each
 configured repository in sequence. (So, not in parallel.) That means—in each
 repository—borgmatic creates a single new backup archive containing all of

docs/how-to/upgrade.md

@@ -145,15 +145,18 @@ like this:
 ```yaml
 location:
     repositories:
-        - original.borg
+        - path: original.borg
 ```
 
+<span class="minilink minilink-addedin">Prior to version 1.7.10</span> Omit
+the `path:` portion of the `repositories` list.
+
 Change it to a new (not yet created) repository path:
 
 ```yaml
 location:
     repositories:
-        - upgraded.borg
+        - path: upgraded.borg
 ```
 
 Then, run the `rcreate` action (formerly `init`) to create that new Borg 2