[FEATURE] Print the `prettier` command to be executed before executing it

[david-allison]

What would you like to change about the program?
Print the prettier command to be executed before executing it

Why do you think this is a cool idea?
New contributors, may not have prettier installed locally and need to set it up. After setup, they need to execute it.

It becomes easier for these contributors to understand what is needed in the execution stage if the full command which prettier_action executes is printed

prettier_action/entrypoint.sh

Lines 72 to 77 in 9561a3f

	echo "Prettifying files..."
	echo "Files:"
	prettier $INPUT_PRETTIER_OPTIONS \
	|| { PRETTIER_RESULT=$?; echo "Problem running prettier with $INPUT_PRETTIER_OPTIONS"; exit 1; }
	echo "Prettier result: $PRETTIER_RESULT"