Update README.md

Sudo for chown
Change to .org
Merge pull request #67 from simeon2020/patch-2

Minor corrections
Update "Playing audio" usage guide

Fixes #68
Remove deprecated GUI tool ImageWriter, close #69
Remove broken link to video streaming
Add link to camera software page
Make CC logo link to licence page
Add installation instructions for NGINX
Merge pull request #73 from mcchots/master

Add installation instructions for NGINX
Fix incomplete sentence
Merge remote-tracking branch 'upstream/master'