Fix so many blurry logos, like DOGE

[CoinSearchr]

The issue appears to be upstream, and may involve one of these options:

• Contact CoinGecko, explain the issue, and get them to find better images
• Start a separate database of images (ideally vector images, where possible)
• Find an alternative provider of images (ideally vector images, where possible)

[CoinSearchr]

Decided that this issue will be fixed by finding vector images, where possible. Moved to Issue #33.