Add .htaccess file to rewrite URLs correctly

[alamb]

• Related to DataFusion blog is broken datafusion#19406

Something has changed in the ASF infrastructure publishing system that changes where our blog content gets published. We need to do this

@Humbedooh suggests on https://issues.apache.org/jira/browse/INFRA-27512

Daniel Gruno added a comment - 26 minutes ago
I would also suggest you commit a .htaccess file to the root (not the output/ dir) of your asf-site branch of the datafusion-site repo, with the following content:

RewriteEngine On
RewriteCond %{ENV:REDIRECT_STATUS} ^$
RewriteRule ^(.*)$ output/$1/ [L]

I pushed this file manually to the asf branch in : 008459f, and 496d3fc

This PR adds it to the source branch