Switched the images of "The keyword of the user query is only displayed in three categories, Topics, Questions and Articles." and "The number of categories the keyword of the user query belongs to is uncertain."
* feat: use @ant-design/icons@4.0
* feat: use createFromIconfontCN to make site works
* feat: update doc for Icon
* feat: use icon in component Alert
* feat: use icon in component Avatar
* feat: use icon in component Breadcrumb
* feat: use icon in component Button
* feat: use icon in component Cascader
* feat: use icon in component Collapse
* feat: use icon in component Datepicker
* feat: use icon in component Dropdown
* feat: use icon in component Form
* feat: use icon in component Input
* feat: use icon in component InputNumber
* feat: use icon in component Layout
* feat: use icon in component Mention
* feat: use icon in component Message
* feat: use icon in component Modal
* feat: use icon in component Notification
* feat: use icon in component PageHeader
* feat: use icon in component Pagination
* feat: use icon in component Popconfirm
* feat: use icon in component Progress
* feat: use icon in component Rate
* feat: use icon in component Result
* feat: use icon in component Select
* feat: use icon in component Step
* feat: use icon in component Switch
* feat: use icon in component Table
* feat: use icon in component Tab
* feat: use icon in component Tag
* feat: handle rest component which using Icon
* fix: remove unused vars
* feat: use latest alpha ant design icons
* fix: failed test in uploadlist.test.js
* test: update snapshot for icons
* doc: add Icon for site
* doc: use @ant-design/icons in site
* chore: use latest icons
* fix: tslint issue
* fix: test cases
* fix: types for react
* fix: lint rules for import orders
* fix: use @ant-design/icons@4.0.0-alpha.5 to avoid insert css in server render
* fix: eslint error in demo/**.md
* inject antd icons
* update snapshot
* fix site
* doc: update docs
* fix: code snippets icon in site
* feat: use latest @ant-design/icons
* fix: icon props in message