README issue with document generation

I was following the instructions on how to generate the documentation for my Ubuntu 20 machine. The README file states that you should go to the build directory and type:

make doxygen
make install

Here is my output:

$ make doxygen
make: *** No rule to make target 'doxygen'.  Stop.

Looking at the Makefile I found there is indeed no target with this name and that in order to generate the documentation I typed:

make docs
make install 

This worked for me. Is this a bug in the README file or what?