Issue 21_Front-end development

• Chapter1 1013-First lesson of school
• 1-1 Development environment: vscode/chrome/phpEnv -1
• 1-2 Development environment: vscode/chrome/phpEnv-2
• 1-3 Learning method: Live broadcast/playback/homework/questions
• 1-4 Markdown common syntax demonstration
• 1-5 Basic knowledge of HTTP and URL01
• 1-6 Basic knowledge of HTTP and URL02
• Chapter2 1014-Elaborate on the basics of html
• 2-1 Review the key points of the first lesson of school 01
• 2-2 Review the key points of the first lesson of school 02
• 2-3 Elements, tags and attributes
• 2-4 HTML document structure, display mode and element type 01
• 2-5 HTML document structure, display mode and element type 02
• 2-6 Page Sambo and Emmet Grammar Practice 01
• 2-7 Page Sambo and Emmet Grammar Practice 02
• Chapter3 1017-Elaborate on HTML5 must-know tags-1
• 3-1 Four major attribute types of html
• 3-2 HTML common element tags: layout class
• 3-3 Common html tags: images, links, lists
• 3-4 Describe tables and common attributes in detail
• 3-5 Describe the form in detail-
  tag and attributes
• Chapter4 1018-Details of form controls
• 4-1 Commonly used form controls 1-1
• 4-2 Commonly used form controls 1-2
• 4-3 Commonly used form controls 1-3
• 4-4 Commonly used form controls 2-1
• 4-5 Commonly used form controls 2-2
• 4-6 Commonly used form controls 2-3
• Chapter5 1019-Other tags and CSS basics
• 5-1 Media tags and