Possible wrong size of chunk in heap section

[Here](https://ir0nstone.gitbook.io/notes/binexp/heap/chunks) you talk about chunks in a x64 bit architecture ([here you say that you'll discuss only x64 bit architectures for your heap section)](https://ir0nstone.gitbook.io/notes/binexp/heap/introduction-to-the-heap).
In particular, at the first link you can read:

> The size field is the overall size of the chunk, including metadata. It must be a multiple of 8, meaning the last 3 bits of the size are 0.

However, I think that in x64 the size of the chunk must be a multiple of 16 bytes and not 8 bytes, because metadata is always 16 bytes and the user data must be a multiple of 16 bytes (ok, if it's a multiple of 16 must be also a multiple of 8, but you got what I mean xD).

In the second link, you stated

> In the following sections, we will only discuss 64-bit systems (with the exception of some parts that were written long ago).

So maybe it's a typo of something written long ago.

Review the heap/chunks page and heap/introduction page linked in the issue, then verify the x64 chunk-size and alignment claim against the surrounding notes or authoritative allocator documentation. Update the inaccurate wording and ensure the two pages are consistent; no code test is mentioned.

Written by the indexing model from the issue text.