Org writer: add support for jupyter nodebook cells.

Closes: #6367

src/Text/Pandoc/Writers/Org.hs

@@ -105,6 +105,14 @@ blockToOrg :: PandocMonad m
            => Block         -- ^ Block element
            -> Org m (Doc Text)
 blockToOrg Null = return empty
+blockToOrg (Div (_, ["cell", "code"], _) (CodeBlock attr t : bs)) = do
+  -- ipynb code cell
+  let (ident, classes, kvs) = attr
+  blockListToOrg (CodeBlock (ident, classes ++ ["code"], kvs) t : bs)
+blockToOrg (Div (_, ["output", "execute_result"], _) [CodeBlock _attr t]) = do
+  -- ipynb code result
+  return $ "#+RESULTS:" $$
+    (prefixed ": " . vcat . map literal $ T.split (== '\n') t)
 blockToOrg (Div attr@(ident,_,_) bs) = do
   opts <- gets stOptions
   -- Strip off bibliography if citations enabled

test/command/6367.md

@@ -0,0 +1,75 @@
+```
+% pandoc -f ipynb -t org
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "A Markdown cell"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "2"
+      ]
+     },
+     "execution_count": 1,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "# A code cell\n",
+    "1 + 1"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Another Markdown cell"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.8.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 4
+}
+^D
+A Markdown cell
+
+#+begin_src jupyter-python
+# A code cell
+1 + 1
+#+end_src
+
+#+RESULTS:
+: 2
+
+Another Markdown cell
+```