Update readme with master checkout before init

Updated readme with command to checkout the remote branch 'master' before running 'git flow init -d'. 

This should fix https://github.com/Teknologforeningen/tf-info/issues/2
Update readme with .env file instructions
Increase calender font-size
Added footer
Merge remote-tracking branch 'upstream/develop' into feature/footer
Merge remote-tracking branch 'upstream/develop' into develop
Merge branch 'feature/footer' into develop