This change makes the start of sharing the docs for the `TimerMode` enum
between Rust and C++. The reference to Timer::start in there works as
both doxygen and rustdoc find the right reference, but this needs
careful editing in the future and double-checking!
Another "caveat" is that the docs for the TimerMode enum say that the
enum is defined in the file "sixtyfps_generated_public.h", which is
correct as-is but not as pretty as "sixtyfps.h". I tried various ways
with \file and \includedoc, but couldn't get it working differently.
To implement this, the cppdocs steps now also runs cbindgen and cbindgen
generates a new sixtyfps_generated_public.h file that contains types we
do want to have in the public sixtyfps namespace.
This reverts commit 0bb904e10a and
re-introduces the markdown table support extension. The resulting table
by default is too wide in the "responsive" read-the-docs theme, but with
a CSS tweak it becomes readable.
Markdown tables are much easier to deal with and this way we can also
include references within the tables.
Tear it out of the CMakeLists.txt and instead run it via
cargo xtask cppdocs
This allows the build_and_test step in the CI to only run cmake for the
library/header related bits and the docs_and_demos step to only generate
docs and not require a full host build of the library (as cargo xtask
cmake would otherwise do).
