Add more examples of arrays to the Cookbook

[novusnota]

As shown here https://github.com/tact-lang/tact/issues/163, we can make something like bit arrays, but allow people to store numbers as byte offsets into the Int type and add subsequent helper wrappers to operate on such "array".

To not pollute global Int method space, we could wrap them into their own struct, like: struct Array32 { u8: Int }.

Additional methods/extension functions could be added, like counting the sum of bytes in the array and such.

P.S.: Solidity has a value/primitive type called Fixed-size byte arrays, which is similar in spirit to what we're trying to do here, so we might just call our arrays the same.