Formatting and minor content fixes

Signed-off-by: Ihor Dvoretskyi <[email protected]>

Author: idvoretskyi

docs/drivers.md

@@ -18,9 +18,23 @@ the host PATH:
 
 To install the KVM2 driver, first install and configure the prereqs:
 
-* Debian or Ubuntu 18.x: `sudo apt install libvirt-clients libvirt-daemon-system qemu-kvm`
-* Ubuntu 16.x or older: `sudo apt install libvirt-bin libvirt-daemon-system qemu-kvm`
-* Fedora/CentOS/RHEL: `sudo yum install libvirt-daemon-kvm qemu-kvm`
+* Debian or Ubuntu 18.x:
+
+```shell
+sudo apt install libvirt-clients libvirt-daemon-system qemu-kvm
+```
+
+* Ubuntu 16.x or older:
+
+```shell
+sudo apt install libvirt-bin libvirt-daemon-system qemu-kvm
+```
+
+* Fedora/CentOS/RHEL:
+
+```shell
+sudo yum install libvirt-daemon-kvm qemu-kvm
+```
 
 Then you will need to add yourself to libvirt group (older distributions may use libvirtd instead)
 
@@ -39,7 +53,7 @@ curl -LO https://storage.googleapis.com/minikube/releases/latest/docker-machine-
 
 NOTE: Ubuntu users on a release older than 18.04, or anyone experiencing [#3206: Error creating new host: dial tcp: missing address.](https://github.com/kubernetes/minikube/issues/3206) you will need to build your own driver until [#3689](https://github.com/kubernetes/minikube/issues/3689) is resolved. Building this binary will require [Go v1.11](https://golang.org/dl/) or newer to be installed. 
 
-```
+```shell
 sudo apt install libvirt-dev
 test -d $HOME/go/src/k8s.io/minikube || \
   git clone https://github.com/kubernetes/minikube.git $HOME/go/src/k8s.io/minikube
@@ -55,6 +69,18 @@ To use the kvm2 driver:
 minikube start --vm-driver kvm2
 ```
 
+or, to use kvm2 as a default driver:
+
+```shell
+minikube config set vm-driver kvm2
+```
+
+and run minikube as usual:
+
+```shell
+minikube start
+```
+
 #### Hyperkit driver
 
 The Hyperkit driver will eventually replace the existing xhyve driver.
@@ -92,6 +118,18 @@ To use the driver:
 minikube start --vm-driver hyperkit
 ```
 
+or, to use hyperkit as a default driver:
+
+```shell
+minikube config set vm-driver hyperkit
+```
+
+and run minikube as usual:
+
+```shell
+minikube start
+```
+
 #### HyperV driver
 
 Hyper-v users may need to create a new external network switch as described [here](https://docs.docker.com/machine/drivers/hyper-v/). This step may prevent a problem in which `minikube start` hangs indefinitely, unable to ssh into the minikube virtual machine. In this add, add the `--hyperv-virtual-switch=switch-name` argument to the `minikube start` command.
@@ -103,6 +141,17 @@ To use the driver:
 ```shell
 minikube start --vm-driver hyperv --hyperv-virtual-switch=switch-name
 ```
+or, to use hyperv as a default driver:
+
+```shell
+minikube config set vm-driver hyperv && minikube config set hyperv-virtual-switch switch-name
+```
+
+and run minikube as usual:
+
+```shell
+minikube start
+```
 
 #### VMware unified driver
 
@@ -131,3 +180,16 @@ To use the driver:
 ```shell
 minikube start --vm-driver vmware
 ```
+
+or, to use vmware unified driver as a default driver:
+
+```shell
+minikube config set vm-driver vmware
+```
+
+and run minikube as usual:
+
+```shell
+minikube start
+```
+