fix: rename default export SVGLint

[regseb]

When importing the default export, it's recommended to use the same name as the exported variable (cf. import-x/no-rename-default).

This package exports a variable named svglint. With the following file:

import SVGLint from "svglint";

const linting = await SVGLint.lintSource("<svg>...</svg>", {
    // ... config object goes here
});

// ...

ESLint and import-x/no-rename-default report this error:

Caution: index.js has a default export svglint. This imports svglint as SVGLint. Check if you meant to write import svglint from 'svglint' instead.

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With this pull request, we will be able to use the name SVGLint.