* add runner args abstraction to allow different args patterns in various terminal apps; fix macOS shm IPC
* extend platform support from Linux to XDG desktop
* update build docs for Unix
* improve terminal args pattern migration for macOS
* Arch Linux packaging; make LIBEXECDIR configurable
* update docs
* resolve libexec and share from relative path
* AppImage packaging
* allow build AppImage on Windows host
- fix: ctrl+click on #include_next header name doesn't open the right file
- enhancement: parser used for non-project C files won't find header files in C++ include folders.