fix contrib/<file>.md errors identified by markdownlint

contrib/network-storage/glusterfs/roles/glusterfs/README.md

@@ -14,12 +14,16 @@ This role performs basic installation and setup of Gluster, but it does not conf
 
 Available variables are listed below, along with default values (see `defaults/main.yml`):
 
+```yaml
 glusterfs_default_release: ""
+```
 
 You can specify a `default_release` for apt on Debian/Ubuntu by overriding this variable. This is helpful if you need a different package or version for the main GlusterFS packages (e.g. GlusterFS 3.5.x instead of 3.2.x with the `wheezy-backports` default release on Debian Wheezy).
 
+```yaml
 glusterfs_ppa_use: yes
 glusterfs_ppa_version: "3.5"
+```
 
 For Ubuntu, specify whether to use the official Gluster PPA, and which version of the PPA to use. See Gluster's [Getting Started Guide](https://docs.gluster.org/en/latest/Quick-Start-Guide/Quickstart/) for more info.
 
@@ -29,9 +33,11 @@ None.
 
 ## Example Playbook
 
+```yaml
     - hosts: server
       roles:
         - geerlingguy.glusterfs
+```
 
 For a real-world use example, read through [Simple GlusterFS Setup with Ansible](http://www.jeffgeerling.com/blog/simple-glusterfs-setup-ansible), a blog post by this role's author, which is included in Chapter 8 of [Ansible for DevOps](https://www.ansiblefordevops.com/).
 

contrib/terraform/aws/README.md

@@ -36,8 +36,7 @@ terraform apply -var-file=credentials.tfvars
 ```
 
 - Terraform automatically creates an Ansible Inventory file called `hosts` with the created infrastructure in the directory `inventory`
-- Ansible will automatically generate an ssh config file for your bastion hosts. To connect to hosts with ssh using bastion host use generated ssh-bastion.conf.
-  Ansible automatically detects bastion and changes ssh_args  
+- Ansible will automatically generate an ssh config file for your bastion hosts. To connect to hosts with ssh using bastion host use generated `ssh-bastion.conf`. Ansible automatically detects bastion and changes `ssh_args`
 
 ```commandline
 ssh -F ./ssh-bastion.conf user@$ip

contrib/terraform/exoscale/README.md

@@ -31,9 +31,7 @@ The setup looks like following
 
 ## Requirements
 
-* Terraform 0.13.0 or newer
-
-*0.12 also works if you modify the provider block to include version and remove all `versions.tf` files*
+* Terraform 0.13.0 or newer (0.12 also works if you modify the provider block to include version and remove all `versions.tf` files)
 
 ## Quickstart
 

contrib/terraform/vsphere/README.md

@@ -35,9 +35,7 @@ This setup assumes that the DHCP is disabled in the vSphere cluster and IP addre
 
 ## Requirements
 
-* Terraform 0.13.0 or newer
-
-*0.12 also works if you modify the provider block to include version and remove all `versions.tf` files*
+* Terraform 0.13.0 or newer (0.12 also works if you modify the provider block to include version and remove all `versions.tf` files)
 
 ## Quickstart