chore: Add LSP console + LS settings in README

[angelozerr]

chore: Add LSP console + LS settings in README

[fbricon]

While you're at it, can you please add this paragraph as well:

#### Testing nightly builds

You can easily install nightly builds from the nightly channel:

- in IntelliJ, open `Setting > Plugins > [Gear icon] > Manage Plugin Repositories...`
- Add `https://plugins.jetbrains.com/plugins/nightly/23257` and press `OK`
<img alt="Nightly Channel Repository" src="images/nightly-channel-repo.png" width="500px" />
- install the latest `LSP4IJ` version

Nightly builds are published once a day.

[angelozerr]

While you're at it, can you please add this paragraph as well:

added