fix: install headers and library (Aaron's version)

[amarburg]

Alternative version of #52

@andresmanelli Since I'm not working with this library in a non-ROS2 context regularly, I'm not entirely sure on best practices for installing binaries. I've modified your suggested PR slightly to use CMAKE defaults for both headers and libraries.

I'm sure there are more sophisticated ways to handle it, but make install correctly installs everything in /usr/local/... Curious if this works for your use case.

[andresmanelli]

Hello @amarburg, if I may, I'd rather see explicitly what and where is something installed, especially since the original PR was not that verbose.

That being said, as the final outcome is the same, it's your call to choose one or the other.

So to answer your question, yes this also works for me :)

[andresmanelli]

Hello @amarburg, I was wondering if this PR or #52 will be merged. Let me know if there is something missing, thanks!

[amarburg]

Ah, sorry, this fell off my plate. I'm going to merge this version as it uses CMake's internal defaults and should be more platform independent.

Thanks for the prompt!