…ormIO registries (#117)

Gets rid of some dumb warnings.

particulary -> particularly
divison -> division
give at significant speedup -> give a significant speedup

* GitHub Action: AVR build & unit test

* Only run benchmark test on Release builds.

* Switch to GitHub actions

* Add manual run

* Use workflow_call instead of workflow_run
workflow_run will "only trigger a workflow run if the workflow file is on the default branch."

* Use the ClangCL toolset on Windows+CLang

* Lookup the C compiler & force build tests on

* Simplify matrix, force tests on & clang fuzzing

* Turn off clang fuzzers -  compilation errors

* Split Windows builds into separate jobs
There is quite a big difference in the compiler toolchains.

* Use marketplace cmake action

* Windows: need to use MSVC command prompt
So compilers are in the path.

* Use MSVC compile options for clang-cl

* Windows: specify generators

* clang-cl: disable __umulh/__mulh intrinsics prior to VS2022

* Sanitize: use target_compile_options & target_link_options

* Build on multiple ubuntu versions

* Speed up canary build

* Launch AVR build only on canary build success

* Reinstate appveyor support

* Update readme Build Status badge

* Add patch version to conform to full semantic versioning spec and build LIBDIVIDE_VERSION from the version components

* GitHub Workflow to create a release PR

* Add GH acation to create a draft release

* Generate a run summary that will be displayed in the GH UI.

* Update documentation: separate out development instructions from usage and use relative links everywhere.

* Typos, prompts, alignment

* Embed version string directly in libdivide.h

* Remove space from filename

* Example commands: remove prompts for easier copy/paste, use 'pwsh' tag for better syntax highlighting

* Add back original doc from ridiculousfish

* Move doc to RELEASE.md

* Improve release type descriptions

* Additional release process details.

* Fix typo

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Co-authored-by: Kim Walisch <kim.walisch@gmail.com>