v2.1.2

Changes since v2.1.1:

• Add a MinGW toolchain file for the Windows cross-check on macOS (7488f80)
• Ignore the _build_win32 directory of the MinGW cross-check (4b3f912)
• Add Paste as Tab-Separated Grid to paste clipboard text as a grid (3b528da)
• Mention the Linux AppImages in the README (77622a6)