update cmakelist by adding loop foreach file

[lekhit]

Advantage 👍

1. no need to keep updating the cmakelist file when new files are added
2. simplified code Disadvantage 👎
3. may be difficult for novice beginner to get understanding

overall 💯

1. hardly anyone likes making changes for every included file in cmake ( me included :)
2. so advantages overweight the odds please consider merging in if you find it useful