Discrepancy between CLI executable name based on install source

[shorsher]

When installing the CLI through homebrew, firefly is the name of the executable. However, ff is the name of the executable when downloading the binary release or using go install.

[EnriqueL8]

If I remember correctly for homebrew it has to be named the same as the package so firefly we can change our go build command inside the Makefile to just output the binary with the name firefly and also the cobra settings.

[dwertent]

The naming convention is derived from the main.go directory's name. To implement a quick fix, we can rename the ff directory to firefly. The remaining time will be focused on updating all occurrences of ff in the documentation to reflect this change.