Investigate vendor bundle size

[freddyheppell]

From a recent prod build

20:37:34.699 | rendering chunks...
-- | --
20:37:35.007 | dist/index.html                  1.66 KiB
20:37:35.008 | dist/manifest.webmanifest        0.41 KiB
20:37:35.012 | dist/assets/index.53ab4696.js    26.48 KiB / gzip: 8.29 KiB
20:37:35.012 | dist/assets/index.07c4418a.css   41.13 KiB / gzip: 6.90 KiB
20:37:35.165 | dist/assets/vendor.f9466277.js   1808.62 KiB / gzip: 662.29 KiB
20:37:35.166 |  
20:37:35.167 | (!) Some chunks are larger than 500 KiB after minification. Consider:
20:37:35.167 | - Using dynamic import() to code-split the application
20:37:35.167 | - Use build.rollupOptions.output.manualChunks to improve chunking: https://rollupjs.org/guide/en/#outputmanualchunks
20:37:35.168 | - Adjust chunk size limit for this warning via build.chunkSizeWarningLimit.

1.8mb pre-gzipping is quite hefty.

Potentially fontawesome?