Fix broken posts

[pkra]

These were broken during the migration from Wordpress.

• [x] http://www.mathjax.org/static-site-generation-for-researchers-an-interview-with-wonseok-shin/
• [x] http://www.mathjax.org/markdown-authoring-as-webapp-an-interview-with-stackedit/
• [x] http://www.mathjax.org/social-media-for-students-and-educators-an-interview-with-demonstranda/
• [x] http://www.mathjax.org/getting-a-response-from-stem-audiences-an-interview-with-letsfeedback/

Check for more -- cf. #23

[pkra]

More breakage

• [X] http://www.mathjax.org/mathjax-community-update-7/
• [x] http://www.mathjax.org/mathjax-community-update-6/
• [x] http://www.mathjax.org/mathjax-v2-3-beta-now-available/
• [x] http://www.mathjax.org/mathjax-v2-2-now-available/
• [x] http://www.mathjax.org/mathjax-v2-2-beta-now-available/
• [x] http://www.mathjax.org/mathjax-v2-0-beta-now-available-on-cdn/
• [x] http://www.mathjax.org/mathjax-version-2-0-now-available/
• [x] http://www.mathjax.org/mathjax-v2-1-beta-now-available-on-the-cdn/

[pkra]

Alright. First round completed.