Add instructions on the readme file

[rudymatela]

Closes #111

This PR adds instructions on how to use Hoff on the README file along with a few other minor README improvements:

• add instructions on the readme file
• remove broken links
• remove the old badge that points to the Travis build of Ruud's repo. Currently is not possible to add a badge for Semaphore due to the project being marked as private there, see issue Public CI for Hoff? #113.

Mr. PR reviewer: you may be interested in looking at the updated readme.md before and/or after looking at the diff.

[rudymatela]

@fatho This is ready for review. Can you please take a look?

Don't forget to look at the rendered readme.md file before approving.

[fatho]

I like it, very clear and succinct 👍

Just some technicalities below:

[rudymatela]

I like it, very clear and succinct +1

Thanks! 😄

[rudymatela]

@OpsBotPrime merge

[OpsBotPrime]

Your merge request has been denied, because merging on Fridays is not recommended. To override this behaviour use the command merge on Friday.

[rudymatela]

@OpsBotPrime merge on friday

[OpsBotPrime]

Pull request approved for merge by @rudymatela, rebasing now.

[OpsBotPrime]

Rebased as 9687649, waiting for CI …