Add support for tables and strike-through text in the XSLT (#117)

* Add support for tables and strike-through text in the XSLT

* Update xml2md.xsl

* Add specific stylesheet for tables and strike-through

* Add comment

tools/xml2md_gfm.xsl

@@ -0,0 +1,80 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!--
+
+xml2md_gfm.xsl
+==============
+
+This XSLT stylesheet is a complement to xml2md.xsl with templates supporting GitHub-flavored Markdown extensions (tables, strike-through).
+
+-->
+
+<xsl:stylesheet
+    version="1.0"
+    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+    xmlns:md="http://commonmark.org/xml/1.0">
+
+
+<!-- Import commonmark XSL -->
+
+<xsl:import href="xml2md.xsl"/>
+<xsl:template match="/">
+  <xsl:apply-imports/>
+</xsl:template>
+
+<!-- params -->
+
+<xsl:output method="text" encoding="utf-8"/>
+
+
+<!-- Table -->
+
+<xsl:template match="md:table">
+    <xsl:apply-templates select="." mode="indent-block"/>
+    <xsl:apply-templates select="md:*"/>
+</xsl:template>
+
+<xsl:template match="md:table_header">
+    <xsl:text>| </xsl:text>
+    <xsl:apply-templates select="md:*"/>
+    <xsl:text>&#xa; | </xsl:text>
+     <xsl:for-each select="md:table_cell">
+     <xsl:choose>
+     <xsl:when test="@align = 'right'">
+     <xsl:text> ---: |</xsl:text>
+     </xsl:when>
+     <xsl:when test="@align = 'left'">
+     <xsl:text> :--- |</xsl:text>
+     </xsl:when>
+     <xsl:when test="@align = 'center'">
+     <xsl:text> :---: |</xsl:text>
+     </xsl:when>
+     <xsl:otherwise>
+     <xsl:text> --- |</xsl:text>
+     </xsl:otherwise>
+     </xsl:choose>
+     </xsl:for-each>
+    <xsl:text>&#xa;</xsl:text>
+</xsl:template>
+
+<xsl:template match="md:table_cell">
+    <xsl:apply-templates select="md:*"/>
+    <xsl:text>| </xsl:text>
+</xsl:template>
+
+<xsl:template match="md:table_row">
+    <xsl:text>| </xsl:text>
+    <xsl:apply-templates select="md:*"/>
+    <xsl:text>&#xa;</xsl:text>
+</xsl:template>
+
+
+<!-- Striked-through -->
+
+<xsl:template match="md:strikethrough">
+    <xsl:text>~~</xsl:text>
+    <xsl:apply-templates select="md:*"/>
+    <xsl:text>~~</xsl:text>
+</xsl:template>
+
+</xsl:stylesheet>