Add markdown format support (#25)

Co-authored-by: Dawid Dziurla <dawidd0811@gmail.com>

node_modules/showdown/test/features/#316.new-simpleLineBreaks-option-breaks-lists.md

@@ -0,0 +1,51 @@
+1. One
+2. Two
+    - A
+    - B
+3. Three
+
+> this has
+> simple linebreaks
+
+    testing
+    some
+    code
+
+ 1. paragraphed list
+
+    this belongs
+    to the first list item
+    
+ 2. This text
+    also
+
+simple
+text
+
+ - a list
+   item
+ - another
+   list item
+
+simple
+text
+
+  - some item
+ 
+    another
+    paragraph
+   
+      - And
+        now
+     
+        paragraph
+        sublist
+     
+          - and
+            even
+       
+            another
+            one
+
+ - foo
+