README update

Author: Dylan Ratcliffe

README.md

@@ -287,6 +287,40 @@ parameters documented above also apply to AIX systems.
 * range (Parameter) - Sets the inter-physical volume allocation policy. AIX only
 * type (Parameter) - Configures the logical volume type. AIX only
 
+## Functions
+
+`lvm::bytes_to_size`: Converts a number of bytes to a size format that LVM can understand e.g. `lvm::bytes_to_size(214748364800)` would return `200g`
+
+`lvm::size_to_bytes`: Converts an LVM size to bytes, the opposite of `lvm::bytes_to_size`.
+
+## Tasks
+
+Documented in the ["Tasks" tab](https://forge.puppet.com/puppetlabs/lvm/tasks) on the forge
+
+## Plans
+
+### `lvm::expand`
+
+Executes common tasks for expanding mounts, this can include:
+
+* Creating PVs
+* Adding PVs to VG
+* Extending LV
+* Extending filesystem
+
+**Parameters:**
+
+`server`: *String* The target for the plan
+
+`volume_group`: *String* The volume group to which the logical volume belongs
+
+`logical_volume`: *String* The logical volume which is to be expanded
+
+`additional_size`: *String* How much size to add to the LV. This should be specified in LVM format i.e. "200m" or "2.5g"
+
+`disks`: *Array[String]* Any physical disks that should be added to the volume group as part of the expand process
+
+`resize_fs`: *Boolean* Whether or not to resize the filesystem
 
 ## Limitations