Because arrays, vectors, and list-style structures in Rust are
zero-index, we need to increment the line number returned by errors
by one so that it represents their actual line numbers.
A basic config parser has been implemented in `config.rs`. It is still
incomplete, but one letter key press bindings in QWERTYUIOP should work
now, along with a command on the next line.
Example `swhkdrc` file that should work:
```
r
alacritty
w
kitty
t
/bin/firefox
```
**TODO:**
- Add more supported key presses (alphabetical, numerical, insert,
home, delete, end, etc)
- Add chained keybindings (`super + g`, `super + 3`)
- Add error handling for parsing the contents of the file
Note: `server.rs` has been modified to add `mod config` at the start of
the file, but it was necessary to do testing for the config parser.