Deleted double tabs

When I copy-pasted one of this examples from the docs as a starting point, they were not accepted until I halved the amount of tabs so I figured that I'd remove them where they came from too. 

Is this correct? And if so, please chack: did I remove ALL the excess tabs correctly?
Bumping version number to 1.6.4
Merge pull request #68 from evertalbers/master

Deleted double tabs
add line to nginx config to fix thumbs problem
Merge pull request #69 from rossriley/nginx-config-update

Add line to nginx config to fix thumbs problem.
Update content.md

Why is this so hard to find?
Update installation.md

You want less whoops after installing
started work on rewrite of extensions section