Update the Templ description with a clearer single-sentence overview and add important links (Docs + X).

Description

I propose we update the description of The Heart with the following cleaner version: --------------------------------------------------------------------------------------------------------------------------- Vitalis — The Living Body. We are building a sovereign, self-sustaining digital organism on-chain. The Heart is its first and sovereign organ. See the Docs → https://vitalis.gitbook.io/docs and follow us on X → https://x.com/vitalisbody --------------------------------------------------------------------------------------------------------------------------- This makes it much clearer for new visitors and provides direct links to documentation and our X account. Vote if you agree.