Make Ext_raw_html default for commonmark format.

changelog

@@ -199,10 +199,12 @@ pandoc (2.1.2)
     + Determine image size for PDFs (#4322).
     + EMF Image size support (#4375, Andrew Pritchard).
 
-  * Text.Pandoc.Extensions: Add `Ext_styles` (Jesse Rosenthal,
-    API change).  This will be used in the docx reader (defaulting to off) to
-    read pargraph and character styles not understood by pandoc (as divs and
-    spans, respectively).
+  * Text.Pandoc.Extensions:
+
+    + Add `Ext_styles` (Jesse Rosenthal, API change).  This will be used in
+      the docx reader (defaulting to off) to read pargraph and character
+      styles not understood by pandoc (as divs and spans, respectively).
+    + Made `Ext_raw_html` default for `commonmark` format.
 
   * Text.Pandoc.Parsing:
 
@@ -1969,7 +1971,7 @@ pandoc (2.0)
   * HTML reader: parse a span with class `smallcaps` as `SmallCaps`.
 
   * LaTeX reader:
- 
+
     + Implemented `\graphicspath` (#736).
     + Properly handle column prefixes/suffixes.  For example, in
       `\begin{tabular}{>{$}l<{$}>{$}l<{$} >{$}l<{$}}`

src/Text/Pandoc/Extensions.hs

@@ -317,6 +317,8 @@ getDefaultExtensions "muse"            = extensionsFromList
                                             Ext_auto_identifiers]
 getDefaultExtensions "plain"           = plainExtensions
 getDefaultExtensions "gfm"             = githubMarkdownExtensions
+getDefaultExtensions "commonmark"      = extensionsFromList
+                                          [Ext_raw_html]
 getDefaultExtensions "org"             = extensionsFromList
                                           [Ext_citations,
                                            Ext_auto_identifiers]