Add PostHog analytics to docs

[mrlubos]

https://umami.is/

Need to check pricing, self-hosting, and alternatives.

[Noah-Haf]

May be more heavy then necessary but a generous free plan: https://posthog.com/pricing

[mrlubos]

@Noah-Haf I was thinking about the docs site here, but I love PostHog and it might actually make sense to adopt it for everything rather than have multiple analytics tools, what do you think? Btw I don't think I have your email/LinkedIn/Discord, right? I'd like to talk more about codegen with you because I know you've been active for a while and sponsored at some point too – thank you for that!

[Noah-Haf]

You can always contact me on discord: noahhaf !