build: Update the build and install instructions

[sbates130272]

Update the top-level README.md to provide clear instructions on how to build and install libvfio-user. Also fix an issue in meson.build caused by an incorrect minimum version check.

[jlevon]

thanks!

[jlevon]

can you explain why this is necessary in a bit more detail please?
This is past the meson version in centos 7

[sbates130272]

@jlevon I am seeing warnings when I build on Ubtuntu because the meson.build file seems to be using features not present in 0.53.0.

[jlevon]

Thanks & sorry for the slow response.

I did a bit of testing, and while meson does complain, this doesn't actually affect a normal build of the library on centos 7. So, overall, I'd prefer to keep running on that and just suck up the warning. Sound OK?

[sbates130272]

@jlevon based on this I will close this PR now. Thanks.

[jlevon]

OK, thanks for contributing!

[sbates130272]

@jlevon this is the warning I get when I do a meson build on Ubuntu 24.04. I would like to avoid this warning by bumping the minimum version in the meson.build file. Or alternatively we suppress this warning? I acknowledge this change causes issues on some distros due to the packaged version of meson being old.

WARNING: Project specifies a minimum meson_version '>= 0.53.0' but uses features which were added in newer versions:
 * 0.57.0: {'exclude_suites arg in add_test_setup'}