add application properties and a ConfigLoader to load set configurations

[fmazmz]

• application-properties.yml: will hold the application configurations
• ConfigLoader.java: Reads the yaml file and maps the config values to a singleton instance of ConfigLoader

Current properties that have been set:

• Server: port & root directory of the static pages
• Logging: log level

@coderabbitai ignore

closes #50

[bamsemats]

I think this looks good, nicely done! Might want to implement tests for getPort and getRootDirectory as well, but maybe that's for another PR?

[annikaholmqvist94]

Nice work! This looks well-structured and adds useful configurability

Clean ConfigLoader implementation with singleton pattern
-Good error handling with meaningful exceptions
Server now accepts configurable port (much more flexible)
-Smart use of getOrDefault for missing config values
As @bamsemats mentioned, tests for getPort() and getRootDirectory(), would be valuable. Could be a follow-up PR.

Overall: Solid implementation that integrates cleanly with existing code
Approved

[annikaholmqvist94]

Nice work! This looks well-structured and adds useful configurability

Clean ConfigLoader implementation with singleton pattern
-Good error handling with meaningful exceptions
Server now accepts configurable port (much more flexible)
-Smart use of getOrDefault for missing config values
As @bamsemats mentioned, tests for getPort() and getRootDirectory(), would be valuable. Could be a follow-up PR.

Overall: Solid implementation that integrates cleanly with existing code
Approved

[fmazmz]

Thanks for the reviews, I figured lets wait with the tests on this class since we will probably update the properties quite a lot going forward, and that means we have to keep updating the tests.
So leaving it for another PR