feat: add support for multiple filters

[thecodrr]

It is now possible to add multiple filters like:

new fdir().filter(p => p.endsWith(".js")).filter(p => p.startsWith(".nim"))

Obviously, you can also do that in a single filter but I think it allows for better readability. The performance hit is also negligible.

[kwaping]

It looks like you decided to implement this as an OR join on the filters. I was trying to use multiple filters in an AND fashion, so that each successive .filter() would further refine the list.

Would it be possible to change the implementation, or add this type of AND filtering?