cosmetic: quoting consistency

site/using-weave/manual-ip-address.md

@@ -16,8 +16,8 @@ Instead of allowing Weave Net to allocate IP addresses automatically (using IPAM
 
 You can specify an IP address and a network explicitly, using Classless Inter-Domain Routing or [CIDR notation](https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing).
 
-For example, we can launch a couple of containers on $HOST1 and
-$HOST2, respectively, with specified IP addresses, as follows...
+For example, we can launch a couple of containers on `$HOST1` and
+`$HOST2`, respectively, with specified IP addresses, as follows...
 
 On `$HOST1`:
 
@@ -26,14 +26,14 @@ host1$ docker run -e WEAVE_CIDR=10.2.1.1/24 -ti ubuntu
 root@7ca0f6ecf59f:/#
 ~~~
 
-And $HOST2:
+And `$HOST2`:
 
 ~~~bash
 host2$ docker run -e WEAVE_CIDR=10.2.1.2/24 -ti ubuntu
 root@04c4831fafd3:/#
 ~~~
 
-Then test that the container on $HOST2 can be reached from the container on $HOST1:
+Then test that the container on `$HOST2` can be reached from the container on `$HOST1`:
 
 ~~~bash
 root@7ca0f6ecf59f:/# ping -c 1 -q 10.2.1.2