add mergerfs readme

roles/mergerfs/README.md

@@ -0,0 +1,25 @@
+mergerfs
+========
+
+Installs mergerfs and mergerfs tools. Creates mountpoints and configures /etc/fstab.
+
+Variables
+---------
+
+`mergerfs_disks`:
+
+    - path: /mnt/disk1
+      disk: /dev/disk/by-id/ata-WDC_WD101EFBX-68B0AN0_VCJW0TDP
+      owner: username # defaults to root
+      group: group    # defaults to root
+      fs: xfs         # defaults to xfs
+      opts: defaults  # defaults to 'defaults'
+      mode: '0770'    # defaults to '0775' 
+
+`mergerfs_fstab`:
+
+    - path: /mergerfs
+      source: /mnt/disk*
+      opts:
+        - minfreespace=1G
+        - fsname=mergerfs