Use DataURI

[hejny]

For simple images use DataURI instead of referencing URL

https://github.com/collboard/collboard/blob/bfb1658d8c91fcf19db093ff3d92a5d71c375374/public/index.html

data:image/svg+xml;base64,PD94bWwgdmVyc2lvbj0iMS4wIj8+PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSI1MDAiIGhlaWdodD0iNTAwIj48ZWxsaXBzZSBzdHlsZT0iZmlsbDojMDAwOyIgY3g9IjI1MCIgY3k9IjI1MCIgcng9IjMzIiByeT0iMzMiPjwvZWxsaXBzZT48L3N2Zz4=