v0.1.18

Upgrade specification to ADIF 3.1.5. See the annotated spec for differences since 3.1.4.
This release contains no other changes to functionality.

Download the version below matching your computer's OS and
processor architecture. Rename the file to adifmt or
adifmt.exe, make it executable with chmod a+x adifmt, and put
it somewhere in your PATH environment like ~/bin/. Verify it
was installed by running adifmt version.

• macOS users: Download adifmt-darwin-arm64 for Macs with M1
  chips or newer. Download adifmt-darwin-amd64 for older Macs.
• Windows users: Download adifmt-windows-amd64 for most modern
  PCs, adifmt-windows-arm64 for tablets and other ARM devices,
  and adifmt-windows-386 for older 32-bit computers.
• Linux users: Download adifmt-linux-arm64 or adifmt-linux-arm
  for Raspberry Pi or other embedded/mobile devices. Otherwise,
  download adifmt-linux-amd64 (64-bit) or `adifmt-linux-386) (32).