Increase version to 12.0.0

[riitasointi]

Description

PR increases version number to 12.0.0 in anticipation of a new stable release

Release notes

General

• Improve support for Windows High Contrast Mode ([Fix] Improve support for Windows High contrast Mode #743)
• Breaking change: Library no longer exports main.css file. Import line for main.css should be removed
  Main.css file contained styles for Reach-dependency that is now removed ([Feature] LanguageMenu without Reach #722)
• Remove ReachUI dependency from the project ([Feature] LanguageMenu without Reach #722)
• Update Styleguidist menu structure and add general library usage documentation to Styleguidist ([Fix] Styleguidist introduction revamp #751)
• Enhance prop descriptions across all components of the library and adjust Styleguidist code block styles ([Feature] Better prop descriptions #757)
• Update dependencies ([Fix] Update dependencies #762)
• Update suomifi-icons to 7.1.0 (Update suomifi-icons dependency to 7.1.0 #768)
• Update Styleguidist component pages and code examples ([Feature] Styleguidist overhaul #766)

LinkList (#710)

• Introduce <LinkList> component

RouterLink (#710)

• Breaking change: Add .fi-link class to the component and use it for styling like in other link components
• Add smallScreen prop to allow smaller font size (16px) where needed

Link & ExternalLink (#710)

• Add smallScreen prop to allow smaller font size (16px) where needed.
• Add option for bulleted variant via variant prop

ActionMenu (#734)

• Introduce <ActionMenu> component

Button

• Breaking change: Rename variant link to secondaryLight ([Breaking change] Rename button's link variant to secondaryLight #742)
• Fix icon vertical alignment ([Fix] Button icon vertical align #770)

LanguageMenu (#722)

• Breaking change: Completely rewrite the component without using ReachUI dependency
  • Rename prop name to buttonText and change its type from any to string. This name better describes its purpose
  • Add mandatory prop aria-label to inform assistive technologies about usage of LanguageMenu
  • Remove props languageMenuButtonClassName and languageMenuOpenButtonClassName
  • Add mandatory lang prop to <LanguageMenuItem>
  • Remove child element <LanguageMenuLink>. All children should now be <LanguageMenuItem>s with an onSelect() handler
  • Add props onBlur(), onClick(), onOpen() and onClose()
  • Add prop wrapperProps which accepts React.HTMLAttributes and is placed to the outermost div of the component
  • Introduce high contrast mode improvements

TextInput, Textarea (#752)

• Add character counter functionality

SingleSelect, MultiSelect (#753)

• Add optional property listProps for passing data-attributes to unordered list element
• Add optional property listItemProps for passing data-attributes to list items

DateInput (#761)

• Fix ref

Breadcrumb (#771)

• Fix underline prop behavior