Pattern config should use path specified as root to do matching

[iboss-ptk]

Currently, if we don't run ficon from the directory that has config file. It will confuse about the relative path specify in the config file.

For example

...
[[for_patterns]]
pattern = "./*.md"
convention = "upper_snake"

It will try to look for anything .md in that directory rather than looking for .md in the path we specify in the command line.