chore(gno.land): enh homepage description

[salmad3]

General enhancements to Gno.land description (and nit picks) -

• Aims to be more direct and remove ambiguity where appropriate.
  • The comma after 'system' in "We’re building Gno.land, the first open-source smart contract system, using Gno," suggests that Gno.land is the first open-source smart contract system.
  • The idea of "'GitHub' of the ecosystem" is effective but is now more approachable.
  • Reduced the use of introductory phrases in sentences for clarity.
  • "Next generation" is appropriate but often over used.
  • Realms are mentioned after the first statement without really making the connection to smart contracts.
• Think its better if the call to action is a separate statement.

[thehowl]

Apologies, can you merge master and ensure that the tests are succeeding? 🙏