Mention endianness and alignment in section ArrayBuffers, binary arrays

* Alignment: My browser (Firefox 87.0 on Linux x86_64) doesn't let me create an unaligned Uint16Array. I. e., `new Uint16Array(b, 1, 1)` on a 4-byte array buffer gives `RangeError: attempting to construct out-of-bounds TypedArray on ArrayBuffer`. In the standard that is [22.2.1.5](https://262.ecma-international.org/6.0/#sec-%typedarray%-buffer-byteoffset-length).13a.

* Endianness: Uint16Array is little-endian on my machine. I just learned that this is machine dependent ([https://stackoverflow.com/questions/7869752/javascript-typed-arrays-and-endianness](Stackoverflow)). In contrast, `dataView.getUint16()` is big-endian, unless the second argument is true.

Hope this helps.

找到標題為「ArrayBuffers, binary arrays」的教學區段，並檢視其中關於型別化陣列和 DataView 的現有說明。加入清楚的註記，涵蓋 issue 中描述的對齊限制和位元組順序差異，包括 Uint16Array 和 dataView.getUint16() 的相關行為。當讀者能夠從該區段理解這兩個注意事項時，即可視為完成。

由索引模型根據 Issue 內容生成。