Remove etcd parameter from default command examples

docs/usage/qemu.en.md

@@ -16,13 +16,16 @@ Old syntax (-drive):
 
 ```
 qemu-system-x86_64 -enable-kvm -m 1024 \
-    -drive 'file=vitastor:etcd_host=192.168.7.2\:2379/v3:image=debian9',
+    -drive 'file=vitastor:image=debian9',
         format=raw,if=none,id=drive-virtio-disk0,cache=none \
     -device 'virtio-blk-pci,scsi=off,bus=pci.0,addr=0x5,drive=drive-virtio-disk0,
         id=virtio-disk0,bootindex=1,write-cache=off' \
     -vnc 0.0.0.0:0
 ```
 
+Etcd address may be specified explicitly by adding `:etcd_host=192.168.7.2\:2379/v3` to `file=`.
+Configuration file path may be overriden by adding `:config_path=/etc/vitastor/vitastor.conf`.
+
 New syntax (-blockdev):
 
 ```
@@ -50,12 +53,12 @@ You can also specify inode ID, pool and size manually instead of `:image=<IMAGE>
 
 ## qemu-img
 
-For qemu-img, you should use `vitastor:etcd_host=<HOST>:image=<IMAGE>` as filename.
+For qemu-img, you should use `vitastor:image=<IMAGE>[:etcd_host=<HOST>]` as filename.
 
 For example, to upload a VM image into Vitastor, run:
 
 ```
-qemu-img convert -f qcow2 debian10.qcow2 -p -O raw 'vitastor:etcd_host=192.168.7.2\:2379/v3:image=debian10'
+qemu-img convert -f qcow2 debian10.qcow2 -p -O raw 'vitastor:image=debian10'
 ```
 
 You can also specify `:pool=<POOL>:inode=<INODE>:size=<SIZE>` instead of `:image=<IMAGE>`
@@ -72,10 +75,10 @@ the snapshot separately using the following commands (key points are using `skip
 `-B backing_file` option):
 
 ```
-qemu-img convert -f raw 'vitastor:etcd_host=192.168.7.2\:2379/v3:image=testimg@0' \
+qemu-img convert -f raw 'vitastor:image=testimg@0' \
     -O qcow2 testimg_0.qcow2
 
-qemu-img convert -f raw 'vitastor:etcd_host=192.168.7.2\:2379/v3:image=testimg:skip-parents=1' \
+qemu-img convert -f raw 'vitastor:image=testimg:skip-parents=1' \
     -O qcow2 -o 'cluster_size=4k' -B testimg_0.qcow2 testimg.qcow2
 ```