Support comments with new lines

[ljacqu]

With string blocks being a thing now, one might want to define a comment as one string with new lines. ConfigMe does not support this—having any comment with new lines in it will just break the export completely. It would be good to revise this.

[ljacqu]

You can now use text blocks to define comments:

    @Comment("""
        Test
        Testeroni""")
    public static final Property<Integer> P = new IntegerProperty("p", 3);

This is equivalent to:

    @Comment({
        "Test",
        "Testeroni"
    })
    public static final Property<Integer> P = new IntegerProperty("p", 3);

With either variant, the resulting YAML is:

# Test
# Testeroni
p: 3