Implement all plugins of ngx-markdown

see: https://jfcere.github.io/ngx-markdown/get-started

• https://jfcere.github.io/ngx-markdown/plugins#emoji
• https://jfcere.github.io/ngx-markdown/plugins#line-numbers
• https://jfcere.github.io/ngx-markdown/plugins#line-highlight
• https://jfcere.github.io/ngx-markdown/plugins#katex