4 render gallery by using art info json

[sc420]

Linked issue: #4

• Add a page /gallery to show a list of art pieces
• Load the art pieces from json with i18n
• Have show more/show less for long description
• Hover the mouse on the image to slightly zoom in
• Show a spinner when loading the json
• Click the image on the art piece to show an image modal

Preview:

Known issues:

• Horizontal scrollbar is shown when the SimpleGrid shows more than 1 row of ArtCard
• Clicking "Show more" would make the description area smaller if the description is too short (not having enough height)