Bug: 404 UX is bad

[bittlingmayer]

Description: The 404 page does not make it easy to create the article. The links don't match the text.

Steps to reproduce the behavior:

1. Go to https://machinetranslate.org/foo
2. Click on "Ask a question about 404"
3. It opens https://github.com/machinetranslate/machinetranslate.org/new/master/index/404.md

Expected behavior: e.g. Upon clicking on the button, a new page should open in Machine Translate’s LinkedIn page.

• The buttons should say "Search the community for foo" and "Ask a question about foo" not "404" and should open the right page
• "you can create it" should say "you can [create the article about foo]".
• "Create this article" should open https://github.com/machinetranslate/machinetranslate.org/new/master/foo.md

Screenshots: