Clarification on Installation step

[jdillard]

For step 3 in the Installation section "Add the binary to $PATH", can that be "Add the binary to $PATH or configure drawio_binary_path"? If so, I can make a PR to add that for clarity.

[modelmat]

sphinxcontrib-drawio/sphinxcontrib/drawio/__init__.py

Lines 208 to 215 in 1f6d77c

	if builder.config.drawio_binary_path:
	binary_path = builder.config.drawio_binary_path
	elif platform.system() == "Windows":
	binary_path = r"C:\Program Files\draw.io\draw.io.exe"
	else:
	binary_path = "/opt/drawio/drawio"
	if not os.path.isfile(binary_path):
	binary_path = "/opt/draw.io/drawio"

I don't actually think $PATH was ever really used past perhaps the very early code.

I'll fix this, so don't worry about it.