title encoding fix

[guycalledseven]

I played with exporter the other night and noticed it did not play well with high utf characters.

fixed title encoding. I had issues with non printable chars (e.g. 
), double quotes ("), single quotes (' and ').. in my titles, causing invalid .md files generation, breaking hugo, looking bad (all titles on site contained codes, not characters) etc.

Added post image to the output. I really am sorry if this is my local thing. I needed it so I exported it like this.

Did boy scouting on Markdownify, merged with latest from the repo.

[SchumacherFM]

Thank you very much for this PR! Looks good to me. I merged it but I can't run the code. If someone complains please stand by to fix it ;-)

[guycalledseven]

Acknowledged. 😀