fix incorrect markdown

doc/user/markdown.md

@@ -67,28 +67,16 @@ GFM honors the markdown specification in how [paragraphs and line breaks are han
 A paragraph is simply one or more consecutive lines of text, separated by one or more blank lines.
 Line-breaks, or soft returns, are rendered if you end a line with two or more spaces:
 
-<<<<<<< HEAD
-[//]: # (Do *NOT* remove the two ending whitespaces in the following line.)
-[//]: # (They are needed for the Markdown text to render correctly.)
-    Roses are red [followed by two or more spaces]
-=======
 <!-- (Do *NOT* remove the two ending whitespaces in the following line.) -->
 <!-- (They are needed for the Markdown text to render correctly.) -->
     Roses are red [followed by two or more spaces]  
->>>>>>> upstream/master
     Violets are blue
 
     Sugar is sweet
 
-<<<<<<< HEAD
-[//]: # (Do *NOT* remove the two ending whitespaces in the following line.)
-[//]: # (They are needed for the Markdown text to render correctly.)
-Roses are red
-=======
 <!-- (Do *NOT* remove the two ending whitespaces in the following line.) -->
 <!-- (They are needed for the Markdown text to render correctly.) -->
 Roses are red  
->>>>>>> upstream/master
 Violets are blue
 
 Sugar is sweet