Add architecture dependent supportability information

[MikeMcC399]

Situation

The README document does not contain information about the supportability of image variants. This can lead to a mismatch of user expectations versus actual supportability.

Suggestion

Add architecture dependent supportability information to the README document based on existing documents.

Architecture builds

versions.json

Platform list

Node.js provides information in the Building Node.js document, Platform list table. Platforms may move between tiers between major release lines:

• v22.x
• v24.x
• v25.x
• v26.x

Architectures

Docker	Node.js	Version	OS	Node.js 22	Node.js 24	Node.js 25	Node.js 26
amd64	x64	glibc	Debian	Tier 1	Tier 1	Tier 1	Tier 1
arm32v7	armv7	glibc	Debian	Tier 1	-	-	-
arm64v8	arm64	glibc	Debian	Tier 1	Tier 1	Tier 1	Tier 1
ppc64le	ppc64le	glibc	Debian	Tier 2	Tier 2	Tier 2	Tier 2
s390x	s390x	glibc	Debian	Tier 2	Tier 2	Tier 2	Tier 2
amd64	x64	musl	Alpine	Experimental	Experimental	Experimental	Experimental
arm32v6	armv6	musl	Alpine	Experimental	-	-	-
arm32v7	armv7	musl	Alpine	Experimental	-	-	-
arm64v8	arm64	musl	Alpine	Experimental	Experimental	Experimental	Experimental
s390x	s390x	musl	Alpine	Experimental	Experimental	Experimental	-

All musl builds are Experimental whether they are built from source or if they are built using https://github.com/nodejs/unofficial-builds outputs. This means all Alpine builds are Experimental as well.

Experimental architectures are not recommended for use with production applications.

Debian architectures

Debian reduces supported architectures when releases transition from End-of-Life to LTS

Debian 11 (bullseye) supports i386, amd64, armhf and arm64