Update README; modify columns CSS

README.md

@@ -1,13 +1,42 @@
 ## MD Composer Extras
 
-Add some formatting option in your Discourse composer : underline, center, align right, justify and strikethrough
+Add some formatting option in your Discourse composer : underline, strikethrough, superscript, subscript, center, align right, justify , float left, float right, and columns.
+
+The CSS for columns and floats is disabled on mobile. By default on mobile columns and float will appear as single column content. The missing CSS can be added in again manually.
+
+## Columns and Floats
+
+When using columns and floats, note that the text will autobreak once an appropriate amount of content has been placed in the second column or to the side of the float.
+
+Columns have a CSS border to for ease of viewing.
+
+A column is broken by placing `[/wrap]` at the end of the first column's content.
+
+**Column Example**
+
+Place the following in your editor to see how columns work.
+
+```
+Test
+
+[wrap="columns"]
+1
+2
+3
+[/wrap]
+1
+2
+3
+
+Test
+```
 
 For more informations, see : 
 
 - English : https://meta.discourse.org/t/md-composer-extras/118912
 - Français : https://www.mon-discourse.fr/themes/md-composer-extras/
 
-<br>
+## Credits
 
 Wrap support by thw26 : https://github.com/thw26
 

desktop/desktop.scss

@@ -1,6 +1,9 @@
 [data-wrap="columns"] {
   width: 50%;
   float: left;
+  border-right: 1px solid black;
+  padding-right: 5px;
+  margin-right: 5px;
 }
 
 [data-wrap="floatl"] {