feat: add support to look for the config file in $XDG_CONFIG_HOME

[timetravel-1010]

Description

Added support to look for the config file in the $XDG_CONFIG_HOME path using the os package.

I've also updated the documentation in the necessary files, I think.

Implements #194

Type of change

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

How Has This Been Tested?

The test suite ran successfully.

I didn't add any unit test in the config_test.go file. I tested (on Ubuntu) putting the .dblab.yaml in my $XDG_CONFIG_HOME path though.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have checked my code and corrected any misspellings

[danvergara]

Just test this out locally.

It worked out!!

Thanks @timetravel-1010!

[timetravel-1010]

Just test this out locally.

It worked out!!

Thanks @timetravel-1010!

You're welcome, happy to help/

P.D: I think #194 can be closed now.