New look for "notes" in SettingsUI

- use <em> to reduce a little bit the font and darken the strings
- <aside> now only works as a regular 'aside' instead of making the text
  italic
- color used (just a darker text-color) #838587
Merge pull request #1046 from MrVaykadji/SettingsUI

New look for "notes" in SettingsUI