✨ Update array storage

[LesterEvSe]

No description provided.

[KyrylR]

Give more explanation why it is hardcoded

[KyrylR]

Suggested change

	// Currently, this value is hardcoded because Simplicity cannot initialize arrays using arguments (i.e., param::LEN).
	// The storage is represented by the 3 u256 "slots", on every transaction all values should be provided in the witness...

I wanted it to be more like an explanation rather then technical description

[KyrylR]

Use Result instead of panic

Suggested change

	/// Adds a given `u64` value to the last 8 bytes (big-endian) of the limb at the specified index.
	///
	/// # Panics
	///
	/// This function **panics** in the following cases:
	/// * **Index out of bounds:** If `index` is greater than or equal to `self.limbs.len()`.
	/// * **Invalid slice length:** If the slice `self.limbs[index][24..]` is not exactly 8 bytes long.
	/// * **Overflow:** If the addition `val += num` overflows `u64::MAX`.
	pub fn add_num_to_last_qword(&mut self, index: usize, num: u64) {
	let mut val = u64::from_be_bytes(self.limbs[index][24..].try_into().unwrap());
	val += num;
	self.limbs[index][24..].copy_from_slice(&val.to_be_bytes());
	}
	/// Adds a given `u64` value to the last 8 bytes (big-endian) of the limb at the specified index.
	///
	/// # Panics
	///
	/// This function **panics** in the following cases:
	/// * **Index out of bounds:** If `index` is greater than or equal to `self.limbs.len()`.
	/// * **Invalid slice length:** If the slice `self.limbs[index][24..]` is not exactly 8 bytes long.
	/// * **Overflow:** If the addition `val += num` overflows `u64::MAX`.
	pub fn set_num_to_last_qword(&mut self, num: u64) {
	let mut val = u64::from_be_bytes(self.limbs[index][24..].try_into().unwrap());
	val += num;
	self.limbs[index][24..].copy_from_slice(&val.to_be_bytes());
	}

Rely on types that Rust provides more pls

[KyrylR]

Give as many context as possible, there should be no "magic" numbers

[KyrylR]

We should explain, what exactly .add_hidden means in that context