docs: update install.md to same content as on lighting-dev-site
docs: update install.md to same content as on lighting-dev-site

It seems that at some point the installation docs of the
https://github.com/lightninglabs/lightning-dev-site/ was identical to
this file (without page navigation + next steps).

Seems that this commit did not get ported to this repo:
https://github.com/lightninglabs/lightning-dev-site/commit/1ad7d3189de6216e769970ce708794b251ec19b5

In this PR the info for macaroons and noencryptwallet is copied over
from the above mentioned commit.

LightningNetwork/lnd,LightningNetwork/lnd,aakselrod/lnd,aakselrod/lnd