Update README

[tidal]

The readme is a bit out of sync with latest development and could use some polishing as well.

• Current requirements to install the library should be documented.
• Maybe add a short documentation of additional (or all) make targets.
• There is a lot of redundancy, which does not really help readability.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[tidal]

@Stale
jehwoandersmakiern!

[yuktea]

@tidal I'll work on this 🙂

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.