v1.1

Externally visible changes since v1.0:

• Added copper::vselect, copper::try_vselect, copper::try_vselect_for, and copper::try_vselect_until. The "select" section in docs/reference.adoc was expanded to include information on the new functions.
• Reduced required CMake version from 3.20 to 3.14.
• Added three options, COPPER_ENABLE_TESTS, COPPER_ENABLE_FLAKY_TESTS, and COPPER_DISALLOW_MUTEX_RECURSION to CMakeLists.txt for easier integration.
• Added new build targets to the Github CI and fixed already existing ones, now covering all mainstream build systems. This information is now also included in docs/techdetails.adoc (previously called benchmark.adoc). Most importantly, Windows builds should now work much better.

v1.0

First release.