General: Instruct file editors not to trim trailing whitespace in mar…

…kdown files.

Two trailing spaces in a markdown file indicates a line break.

Props netweb

Fixes #43104


git-svn-id: https://develop.svn.wordpress.org/trunk@42862 602fd350-edb4-49c9-b593-d223f7449a82

.editorconfig

@@ -17,5 +17,8 @@ indent_style = tab
 indent_style = space
 indent_size = 2
 
+[*.md]
+trim_trailing_whitespace = false
+
 [{*.txt,wp-config-sample.php}]
 end_of_line = crlf