* Fix markdown renderer
Use a simple for loop instead of `for (var target of markdownTargets)`, because it's unsupported in IE.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...of#Browser_compatibility
* view.html : HTML Fixes
- Remove unmatched `</a>`
- Add missing `</div>`
- Use single quotes in {{ }}
- Closing tags comments
* layout.html
- Use single quotes in {{ }}
- Closing tags comments
* help.html: Convert all `<p>` to `<div>`
HTML spec doesn't allow lists inside `<p>` elements.
* Missing semicolon in `<script>`
These changes add a macro that creates the relevant HTML markup for a
markdown editor. In the main.js file, we bind the relevant elements with
the marked library, so users can see their contents in a HTML format.
