Add documentation for linux/samba/chain_reply module (CVE-2004-0883)

[DataExplorerX]

What does this PR do?

Adds comprehensive documentation for the linux/samba/chain_reply module (CVE-2010-2063).

No code changes - pure documentation addition.

Verification

Docs-only PR - no functional changes to test.

• Documentation added for undocumented module [file:85]
• Matches existing Samba docs format (is_known_pipename.md)
• Includes CVE, targets, options, scenarios, technical details
• Follows Metasploit documentation standards

Verification Steps (for reviewers):
cd metasploit-framework
ls documentation/modules/exploit/linux/samba/chain_reply.md # ✅ Exists
cat documentation/modules/exploit/linux/samba/chain_reply.md # ✅ Complete

Why this matters: Module existed without docs. Users can now understand:

• Samba < 3.3.13 (port 139, x86 Linux)
• talloc destructor overwrite technique
• Brute force exploitation (Offset2=0x1fec)
• Debian 5 target details