Check for .markdownlint.jsonc file by default

[jjspace]

The tool has the ability to parse a jsonc file but it doesn't look for it by default. This is one of the default configuration filenames that the vscode extension checks for so I had expected it to work.

I think it should just be a matter of changing:

markdownlint-cli/markdownlint.js

Line 38 in 1e7ba15

const projectConfigFiles = ['.markdownlint.json', '.markdownlint.yaml', '.markdownlint.yml'];

To

const projectConfigFiles = ['.markdownlint.json', '.markdownlint.jsonc', '.markdownlint.yaml', '.markdownlint.yml'];

[DavidAnson]

That change makes sense, though I would put the new entry at the end of the list so it doesn't suddenly take precedence in cases where such a file is already present.

FYI, if you want the best compatibility with the VS Code extension, markdownlint-cli2 uses the same engine: https://github.com/DavidAnson/markdownlint-cli2