some features and fixes

[pduchnovsky]

Prerequisites

• This pull request adds a feature.
• This pull request fixes certain issues.

Description

• Some very minor changes in css
• Removed prefetch-src CSP since its deprecated and unsupported by any browser
• Added support for "mailto:" e.g. 'Contact me' menu links.
  e.g.:
• Lowered text size of footer on mobile devices.
  e.g. before and after:
  

Issues Resolved

• Defined avatar width and height so content doesn't 'jump' during page/image loading.
• Added pagination li padding for more easily 'clickable' pagination links on mobile devices and some other minor changes.
  e.g. before and after:
  
• Increased size of avatar on mobile devices so it does not look so small.
  e.g. before and after:
  

Checklist

General

• Describe what changes are being made
• Explain why and how the changes were necessary and implemented respectively

Resources

• If you have changed any SCSS code, run make release to regenerate all CSS files

[luizdepra]

I'm going to need to merge this PR in a separated branch, and then I can cherry-pick the changes I find interesting.
I'll come back here later.

[pduchnovsky]

Just a note, this is ready to be merged still :D I think the changes are pretty useful, not sure what's the blocker ¯_(ツ)_/¯