docs(readme): fix broken link to installation of binaries page

[petermetz]

## Besu Users

To install the Besu binary, follow [these instructions](https://besu.hyperledger.org/HowTo/Get-Started/Install-Binaries/).    

The broken link: https://besu.hyperledger.org/HowTo/Get-Started/Install-Binaries/

I'm guessing the correct ones are these (they appear to have the exact same content)

• https://besu.hyperledger.org/private-networks/get-started/install/binary-distribution
• https://besu.hyperledger.org/public-networks/get-started/install/binary-distribution