Rendering speed fixes

[ARBaart]

Fixes #40 and #44, improves #63 enough to have it no longer be a priority.

Changes:

• header video only loads metadata at first, playback is started only when all else has loaded
• board picture is now much smaller jpeg version
• CSS is separated out of the html and unused items are purged
• small dayjs package replaces momentjs for time parsing and formatting

Remaining:

• The vue-zondicons package loads all icons regardless of which are used, but there is no setting for it
• Some clever image preview/resizing package could remove the need for supplying them in an agreeable size and format

[casperboone]

Cool, nice finds, thx :). Really thought I had already enabled Purge CSS, quite a must when using Tailwind 😅.