KOB-32547 Enhance the UI/UX for Help Widget

[tamdao]

https://kobiton.atlassian.net/browse/KOB-32547

This PR to fix some issues:

• style not follow new design
• missing css of code snippet component
• add api document into home widget page

[tamdao]

@tamdao LGTM, but please add a 1 sentence description that describes these changes. Thanks!

Sure