Fix whitespace hacks

[jarhodes314]

Now sveltejs/prettier-plugin-svelte#24 is resolved, we can:

• Make sure we are using the latest version of prettier-plugin-svelte
• Remove the nasty regex to replace whitespace in the rollup config
• Replace the  s and  s with actual whitespace (unless there are any where we have some weird double spacing requirements, but I don't think there are)
• Fix all the spacing around punctuation (e.g. in the footer, which is where the entire problem began). Possibly a good idea to try and (ab)use the regex in the rollup config as a way of searching for this.