SSR guide: add missing parts

[NataliaTepluhina]

We have to extend the SSR guide with missing important parts

• CSS Management
• Head management
• Caching
• Streaming
• Data fetching and local store
• Error handling

[CyberAP]

I'd also add error handling here as well because it depends on the execution environment (we might want to show a toast on a client or render an error on the server).

[NataliaTepluhina]

@CyberAP added!

[runxc1]

So going through the documentation I am running into a lot of little items that are taking an hour here or two hours there even though I had set this up using VueJs 2 a while ago and am not new to the process. I'm still looking for the way to get the CSS as @vue/server-renderer's renderToString does not include the CSS