Changed the usage from `add_libweb_test.py test_name.html` to
`add_libweb_test.py test_name.html test_type` with no default,
and supports automatically generating input/output files in the
right directories for test types Screenshot, Text, Ref, and Layout.
Co-authored-by: Sam Atkins <sam@ladybird.org>
The reason for this change is that CMake/vcpkg are unable to detect a
change to VCPKG_LIBRARY_LINKAGE. So when we switch to dynamic builds,
the switch would be non-functional, and every developer would have to
remove their Build and vcpkg cache directories manually. By changing
these directories, vcpkg is able to detect it must rebuild.
Bring together the docs on running tests, with the ones on writing them
which were hidden in Browser/Patterns.md
I've made a few adjustments while I was at it, because RunningTests.md
was a bit outdated and didn't mention `Meta/ladybird.sh test`. It's
possible they're still outdated and wrong, but I'm not familiar enough
with that area to know.
