HTML preview is not UTF-8

[Louson]

If I export the md file with 'markdown-preview', the specials characters are not correctly read on my browser (firefox 60.0.1)

Expected Behavior

Export a md file containing letters with accents should be read in a browser supporting UTF-8.

Actual Behavior

The html output should support UTF-8

Steps to Reproduce

1. Create a markdown file containing letters with accents

This is special letter é

2. Export with 'markdown-preview' command
3. Open with firefox

Software Versions

Markdown v2.1
Emacs 25.3.1

Possible solution

I don't know much about HTML but I guess it misses a line before the title (markdown-mode.el:markdown-add-xhtml-header-and-footer :

<meta charset=\"UTF-8\"/>

Also, I don't know why the html starts with an xml header specifing the UTF-8...

[jrblevin]

This should be fixed by #350, but please reopen if not.