Update HowTo.md
Add XSLT file reference
2. From the shown nodes, choose the body element and from the context menu choose 'copy element'
3. Copy it into the [template](template.html)
4. Make it XML by replacing &lt;br&gt; with &lt;br/&gt; (likely that's all)
-4. Change correct indent from tab to 4 Space (only necessary for ODF 1.2 parts - easy with UltraEdit ^t)
+4. Change correct indent from tab to 4 spaces (only necessary for ODF 1.2 parts - easy with UltraEdit ^t)
5. Place the created HTML into the appropriate folder, e.g. '[xslt-runner/src/test/resources/odf13](../../../src/test/resources/odf13)'
6. If necessary adopt the new input path in the [pom.xml](../../../pom.xml)
-7. Do XSL transformation via Maven 'mvn clean install' to add IDs for RelaxNG Defines & HRefs for RelaxNG refs
+7. Trigger an [XSL transformation](../../../sample_xslt/rng/rng2html.xsl) via Maven 'mvn clean install' to add IDs for RelaxNG Defines & HRefs for RelaxNG refs
8. Copy the [sample_xslt/rng/view-source.css](../../../sample_xslt/rng/view-source.css) to the new created output target\generated-resources\xml\xslt)
**NOTE:**
