Disabling zooming is problematic for people with low vision (https://dequeuniversity.com/rules/axe/3.0/meta-viewport).

Fixes #49

The former will be deprecated and eventually removed from Hugo.

Note: Currently both of them exist in Hugo, which is the reason for the cleanup.

The header should use the language supplied in the configuration rather than hardcoding to english (US).

The original reference was to favicon.ico, when the provided image is .png

CSS is now split into poole.css and hyde.css; chrome/sidebar.html updated.

Also cherry-pick:

  * poole/hyde@48b9d1f - Set a max-width for images