Decode 3.0.0

## Added:
- iTunes social link
- Bandcamp social link
- Added Simplified Chinese translation
- British-specific spellings
- Added proper X-UA-Compatible meta tags
- Filters for most theme setup functions

## Improved:
- Greatly simplified customizing by hiding options when they will not display a result on the site. e.g. Removing social links from display will hide each individual social link option too.
- New default color scheme
- Color controls have added descriptions with tips on finding a good color selection.
- Customizer controls use appropriate keyboards on touch devices.
- Hide "Edit" button in print
- Accessibility improvements (buttons now have `<button>` markup and title attributes, etc.)
- Custom CSS doesn't output anything if there is no input
- No IDs in CSS

## Fixed:
- Inputs use same font
- Goodreads icon changes color now
- No margin appearing between a menu with only two items in RTL text.
- RTL spacing in social icons fixed
- Height of textarea is no longer the same as other inputs

## Changed:
- Now, only latin characters are loaded by default, if you need additional characters, check the option in Customizer > Content Options > Load Latin Extended character set
- A few selectors have had their names changed, custom CSS needs to be updated accordingly, but will continue to work until the next version:
SidebarLink -> sidebar-link
SidebarTop -> sidebar-top
SidebarClose -> sidebar-close
SidebarContent -> sidebar-content
SidebarMenuTrigger -> menu-icon
SidebarMenuClose -> close-icon
SocialIconFill -> social-icon-fill