Version 0.20.0

Changes:

• ⚠️ doctest’s source files are now ECMAScript modules (#146)
• ⚠️ --coffee is now necessary to test CoffeeScript files (#152)
• ⚠️ doctest no longer supports AMD (#157)
• ⚠️ doctest now provides richer representations of test results (#164)
• ⚠️ output lines must now be contiguous with input lines (#155)
• --type js is now assumed for files without extensions (#149)
• exit code is now 0 if no files are specified (#150)
• doctest no longer creates temporary files (#165)
• __filename now refers to the source file rather than a temporary file (#165)
• doctest now supports CommonJS modules written in CoffeeScript (#165)
• doctest now supports ECMAScript 2023 (#173)
• acorn dependency upgraded from 8.5.x to 8.11.x (#166)
• coffeescript dependency upgraded from 1.12.x to 2.7.x (#153, #167)
• sanctuary-show dependency upgraded from 2.0.x to 3.0.x (#168)
• sanctuary-type-classes dependency upgraded from 12.1.x to 13.0.x (#169)