Merge pull request #3333 from thaJeztah/docs_checkpoint_fixups

docs: some minor touch-ups in checkpoint reference

docs/reference/commandline/checkpoint.md

@@ -18,14 +18,14 @@ checkpoint and restore in Docker is available in this
 
 ### Installing CRIU
 
-If you use a Debian system, you can add the CRIU PPA and install with apt-get
+If you use a Debian system, you can add the CRIU PPA and install with `apt-get`
 [from the criu launchpad](https://launchpad.net/~criu/+archive/ubuntu/ppa).
 
 Alternatively, you can [build CRIU from source](https://criu.org/Installation).
 
-You need at least version 2.0 of CRIU to run checkpoint/restore in Docker.
+You need at least version 2.0 of CRIU to run checkpoint and restore in Docker.
 
-### Use cases for checkpoint & restore
+### Use cases for checkpoint and restore
 
 This feature is currently focused on single-host use cases for checkpoint and
 restore. Here are a few:
@@ -35,21 +35,22 @@ restore. Here are a few:
 - "Rewinding" processes to an earlier point in time
 - "Forensic debugging" of running processes
 
-Another primary use case of checkpoint & restore outside of Docker is the live
+Another primary use case of checkpoint and restore outside of Docker is the live
 migration of a server from one machine to another. This is possible with the
 current implementation, but not currently a priority (and so the workflow is
 not optimized for the task).
 
-### Using checkpoint & restore
+### Using checkpoint and restore
 
 A new top level command `docker checkpoint` is introduced, with three subcommands:
-- `create` (creates a new checkpoint)
-- `ls` (lists existing checkpoints)
-- `rm` (deletes an existing checkpoint)
 
-Additionally, a `--checkpoint` flag is added to the container start command.
+- `docker checkpoint create` (creates a new checkpoint)
+- `docker checkpoint ls` (lists existing checkpoints)
+- `docker checkpoint rm` (deletes an existing checkpoint)
 
-The options for checkpoint create:
+Additionally, a `--checkpoint` flag is added to the `docker container start` command.
+
+The options for `docker checkpoint create`:
 
 ```console
 Usage:  docker checkpoint create [OPTIONS] CONTAINER CHECKPOINT
@@ -66,7 +67,7 @@ And to restore a container:
 Usage:  docker start --checkpoint CHECKPOINT_ID [OTHER OPTIONS] CONTAINER
 ```
 
-Example of using checkpoint & restore on a container:
+Example of using checkpoint and restore on a container:
 
 ```console
 $ docker run --security-opt=seccomp:unconfined --name cr -d busybox /bin/sh -c 'i=0; while true; do echo $i; i=$(expr $i + 1); sleep 1; done'
@@ -79,7 +80,7 @@ $ docker start --checkpoint checkpoint1 cr
 abc0123
 ```
 
-This process just logs an incrementing counter to stdout. If you `docker logs`
+This process just logs an incrementing counter to stdout. If you run `docker logs`
 in between running/checkpoint/restoring you should see that the counter
 increases while the process is running, stops while it's checkpointed, and
 resumes from the point it left off once you restore.