feat: add config shorthand

[lvlcn-t]

Motivation

To add a -c flag shorthand for the config. We should have this since it's a common flag that is always passed to the CLI and it's cumbersome to always write the whole --config flag everytime you want to run sparrow.

Changes

Added a shorthand for the --config flag.

For additional information look at the commits.

Tests done

New help description reflects the new shorthand:

❯ go run . 
Sparrow is an infrastructure monitoring agent that is able to perform different checks.
The check results are exposed via an API.

Usage:
  sparrow [command]

Available Commands:
  completion  Generate the autocompletion script for the specified shell
  help        Help about any command
  run         Run sparrow

Flags:
  -c, --config string   config file (default is $HOME/.sparrow.yaml)
  -h, --help            help for sparrow

Use "sparrow [command] --help" for more information about a command.

❯ go run . run -c ./.tmp/config/start.yaml
Using config file: ./.tmp/config/start.yaml
{"time":"2024-10-15T23:42:07.797637971+02:00","level":"INFO","source":{"function":"github.com/caas-team/sparrow/cmd.NewCmdRun.run.func1","file":"/home/tom/dev/sparrow/cmd/run.go","line":89},"msg":"Running sparrow"}

• Unit tests succeeded - Not applicable
• E2E tests succeeded - Not applicable

TODO

• I've assigned this PR to myself
• I've labeled this PR correctly