docs: add guide for hexdump formatting

Author: MrIndeciso

docs/advanced/hexdump.md

@@ -0,0 +1,57 @@
+# Hex Dump
+
+Every libdestruct object has a `hexdump()` method that returns a classic hex dump of its serialized bytes.
+
+## Basic Usage
+
+```python
+from libdestruct import c_int, inflater
+
+memory = bytearray(b"Hello, World!\x00\x00\x00")
+lib = inflater(memory)
+x = lib.inflate(c_int, 0)
+print(x.hexdump())
+```
+
+Output format:
+
+```
+00000000  48 65 6c 6c                                       |Hell|
+```
+
+Each line shows: offset, hex bytes (up to 16 per line), and ASCII representation (non-printable bytes shown as `.`).
+
+## Struct Hex Dump
+
+When called on a struct, `hexdump()` annotates each line with the field names that start on that line:
+
+```python
+from libdestruct import struct, c_int, c_long
+
+class player_t(struct):
+    health: c_int
+    score: c_long
+
+memory = bytearray(12)
+memory[0:4] = (100).to_bytes(4, "little")
+memory[4:12] = (9999).to_bytes(8, "little")
+
+player = player_t.from_bytes(memory)
+print(player.hexdump())
+```
+
+Output:
+
+```
+00000000  64 00 00 00 0f 27 00 00 00 00 00 00               |d....'......|  health, score
+```
+
+## Standalone Utility
+
+The underlying `format_hexdump` function can be used directly:
+
+```python
+from libdestruct.common.hexdump import format_hexdump
+
+print(format_hexdump(b"\xde\xad\xbe\xef", base_address=0x1000))
+```