Integrate rich-markdown-editor to create Articles

[bryanwong8]

Is your feature request related to a problem? Please describe.
We need to implement a MD editor for people to write Articles on our app.

Describe the solution you'd like

• Integrate rich-markdown-editor
• https://github.com/outline/rich-markdown-editor

Figma Design
Figma link: https://www.figma.com/file/pyXHrfSlr2xx3xunNXjcpx/New-UI?node-id=2694%3A727
For now, create a component to contain the MD editor and center it in the middle of the page.

Component Details

• Create a component to contain the MD editor.
• Figure out logic to implement the MD editor
• I would recommend looking at this example, https://github.com/outline/rich-markdown-editor/blob/master/example/src/index.js, on how the MD editor works