doc: add a note about uv_dirent_t.type
doc: add a note about uv_dirent_t.type

On Linux getting the type is only supported by some filesystems, check
getdents(2).

unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso