Optimize all flag images

[danielgomezrico]

I found that you can have more optimized resources and therefore they take less time to render, less memory in ram and less apk size at the end.

I applied some optimizations from this imageoptim.com tool which does not make the images ugly but only compress them.

Results

Saved 229 KB out of 479 KB. 54,2 % per file on average (up to 86,5 %)

[danielgomezrico]

BTW is there any chance that you add a label hacktoberfest-accepted to this PR so it counts for this https://hacktoberfest.digitalocean.com ?

[imtoori]

thanks a lot @danielgomezrico