fix(common) Remove extra newline when printing thematic breaks

Signed-off-by: Jerome Simeon <[email protected]>

Author: jeromesimeon

packages/markdown-common/src/ToMarkdownStringVisitor.js

@@ -167,7 +167,7 @@ class ToMarkdownStringVisitor {
             break;
         case 'ThematicBreak':
             ToMarkdownStringVisitor.newBlock(parameters,2);
-            parameters.result += '---\n';
+            parameters.result += '---';
             break;
         case 'Linebreak':
             parameters.result += '\\\n';