Adds AltArch (32-bit) SIG proposal doc (#738)

* Adds AltArch (32-bit) SIG 

---------

Co-authored-by: Andrew Lukoshko <andrew.lukoshko@gmail.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

Author: 3 people

docs/sigs/AltArch.md

@@ -0,0 +1,43 @@
+---
+title: "AltArch SIG"
+---
+
+# AltArch SIG
+
+The purpose of this SIG is to maintain support for alternate (non-mainstream) architectures like x86_32 and Raspberry Pi.
+This SIG will work in close collaboration with the Core SIG to ensure all builds remain synchronized with the AlmaLinux OS 10 releases and maintains compatibility with RHEL ecosystem standards.
+
+## How to Join
+
+Joining is easy! You can show up to a meeting, pick up an issue from the list by assigning it to yourself, or ask questions in chat! Not every contributor wants to be a part of the SIG, but if you do, joining is simple.
+
+**Where we chat**
+
+The AltArch SIG uses [AltArch](https://chat.almalinux.org/almalinux/channels/sigaltarch) chat channel for communication.
+
+**Where and when we meet**
+
+Meetings will be held bi-weekly, with timing adjusted to accommodate members across different time zones. We also work asynchronously in Mattermost to accomplish our goals between meetings.
+
+## Activities, projects, and deliverables
+
+- Maintain synchronization with AlmaLinux 10 minor releases
+- Security patch backporting and testing
+- Community support for platforms like x86_32 and Raspberry Pi
+- Maintain selected packages from the epel 10 repository for alternate archs
+
+### Help wanted
+
+Contributions take all kinds of shapes and sizes, and we welcome everyone! If you have expertise or time and would like to help us out, please join us at [AltArch SIG on Mattermost](https://chat.almalinux.org/almalinux/channels/sigaltarch)
+
+## SIG members
+
+- [Peter Edwards](peadar@arista.com) - SIG Lead x86_32 building
+- [Eduard Abdullin](eabdullin@almalinux.org) - SIG Lead x86_64-v2 building
+- [Andrew Lukoshko](alukoshko@almalinux.org) - SIG Lead RISC-V building
+- [Koichiro Iwao](koichiro.iwao@miraclelinux.com) - SIG Lead - Raspberry Pi building
+- [Ganesan Rajagopal](rganesan@arista.com) - Member
+- [Navneet Sinha](navneet@arista.com) - Member
+- [Anant Verma](anantv@arista.com) - Member
+- [Mahendar Srinivasan](mahendars@arista.com) - Member
+- [Michel Lind](michel@michel-slm.name) - Member