minor docs issue about prerequisites

[ericm1024]

I'm trying to install librseq on a fresh ubuntu server VM.

I followed the instructions in the README, but needed to additionally install make (duh, oops) and libnuma-dev (though it told me how to proceed if I didn't have this).

In particular, the error when you try to run ./configure without make installed is shockingly obtuse.

config.status: error: in '/home/eric/librseq':
config.status: error: Something went wrong bootstrapping makefile fragments
    for automatic dependency tracking.  If GNU make was not used, consider
    re-running the configure script with MAKE="gmake" (or whatever is
    necessary).  You can also try re-running configure with the
    '--disable-dependency-tracking' option to at least be able to build
    the package (albeit without support for automatic dependency tracking).
See 'config.log' for more details

Neither of these are a big deal but it might be nice to add these to the "Prerequisites" section of the README. I'm happy to spin the patch for this if this is acceptable.

Thanks for all your years of effort on this great project, looking forward to playing around with it.