Add markdown help

This change adds markdown help for all added functions. It also adds
a step in the build process to create the MAML XML file.

Author: SeeminglyScience

PowerShellEditorServices.build.ps1

@@ -196,6 +196,8 @@ task LayoutModule -After Build {
         Copy-Item -Force -Path $PSScriptRoot\src\PowerShellEditorServices.Host\bin\$Configuration\net451\Newtonsoft.Json.dll -Destination $PSScriptRoot\module\PowerShellEditorServices\bin\Desktop\
     }
     Copy-Item -Force -Path $PSScriptRoot\src\PowerShellEditorServices.Host\bin\$Configuration\netstandard1.6\* -Filter Microsoft.PowerShell.EditorServices*.dll -Destination $PSScriptRoot\module\PowerShellEditorServices\bin\Core\
+
+    New-ExternalHelp -Path $PSScriptRoot\module\docs -OutputPath $PSScriptRoot\module\PowerShellEditorServices\Commands\en-US -Force
 }
 
 task PackageNuGet {

module/docs/ConvertFrom-ScriptExtent.md

@@ -0,0 +1,146 @@
+---
+external help file: PowerShellEditorServices.Commands-help.xml
+online version:
+schema: 2.0.0
+---
+
+# ConvertFrom-ScriptExtent
+
+## SYNOPSIS
+
+Converts IScriptExtent objects to some common EditorServices types.
+
+## SYNTAX
+
+### BufferRange
+
+```powershell
+ConvertFrom-ScriptExtent -Extent <IScriptExtent[]> [-BufferRange] [<CommonParameters>]
+```
+
+### BufferPosition
+
+```powershell
+ConvertFrom-ScriptExtent -Extent <IScriptExtent[]> [-BufferPosition] [-Start] [-End] [<CommonParameters>]
+```
+
+## DESCRIPTION
+
+Translates IScriptExtent object properties into constructors for some common PowerShell EditorServices types.
+
+## EXAMPLES
+
+### -------------------------- EXAMPLE 1 --------------------------
+
+```powershell
+$sb = { Get-ChildItem 'Documents' }
+$sb.Ast | Find-Ast { $_ -eq 'Documents' } | ConvertFrom-ScriptExtent -BufferRange
+```
+
+Gets the buffer range of the string expression "Documents".
+
+## PARAMETERS
+
+### -Extent
+
+Specifies the extent to be converted.
+
+```yaml
+Type: IScriptExtent[]
+Parameter Sets: (All)
+Aliases:
+
+Required: True
+Position: Named
+Default value: None
+Accept pipeline input: True (ByPropertyName, ByValue)
+Accept wildcard characters: False
+```
+
+### -BufferRange
+
+If specified will convert extents to BufferRange objects.
+
+```yaml
+Type: SwitchParameter
+Parameter Sets: BufferRange
+Aliases:
+
+Required: False
+Position: Named
+Default value: False
+Accept pipeline input: False
+Accept wildcard characters: False
+```
+
+### -BufferPosition
+
+If specified will convert extents to BufferPosition objects.
+
+```yaml
+Type: SwitchParameter
+Parameter Sets: BufferPosition
+Aliases:
+
+Required: False
+Position: Named
+Default value: False
+Accept pipeline input: False
+Accept wildcard characters: False
+```
+
+### -Start
+
+Specifies to use the start of the extent when converting to types with no range. This is the default.
+
+```yaml
+Type: SwitchParameter
+Parameter Sets: BufferPosition
+Aliases:
+
+Required: False
+Position: Named
+Default value: False
+Accept pipeline input: False
+Accept wildcard characters: False
+```
+
+### -End
+
+Specifies to use the end of the extent when converting to types with no range.
+
+```yaml
+Type: SwitchParameter
+Parameter Sets: BufferPosition
+Aliases:
+
+Required: False
+Position: Named
+Default value: False
+Accept pipeline input: False
+Accept wildcard characters: False
+```
+
+### CommonParameters
+
+This cmdlet supports the common parameters: -Debug, -ErrorAction, -ErrorVariable, -InformationAction, -InformationVariable, -OutVariable, -OutBuffer, -PipelineVariable, -Verbose, -WarningAction, and -WarningVariable. For more information, see about_CommonParameters (http://go.microsoft.com/fwlink/?LinkID=113216).
+
+## INPUTS
+
+### System.Management.Automation.Language.IScriptExtent
+
+You can pipe IScriptExtent objects to be converted.
+
+## OUTPUTS
+
+### Microsoft.PowerShell.EditorServices.BufferRange
+
+### Microsoft.PowerShell.EditorServices.BufferPosition
+
+This function will return an extent converted to one of the above types depending on switch
+choices.
+
+## NOTES
+
+## RELATED LINKS
+