Improve support for languages which don't appear in Helix' default languages.toml

[senekor]

We cannot easily support arbitrary languages that Helix doesn't support (i.e. that don't show up in the default languages.toml). Specifically, they will be ignored if their settings only appear in the global ([*]) section of the .editorconfig file.

These are probably niche or "underspecified" languages. To support them, a list of their file globs is hardcoded. And example is *.txt.

Please comment with file types you would like to be supported this way.

[senekor]

There is no need anymore to hardcode all possible globs, users can specify them according to their own needs with ec2hx --fallback-globs.

Feel free to still comment here if you think a specific glob is worth including by default / hardcoding for everyone.