Docker multiarch (#93)

* Reshot screenshots on an english system (also added GIMP files)

* Added multiarch to minimal

* Added amd64 suffix

* Stripped down file (comments are inside the README anyways)

* Added python3 multiarch

* Corrected missing arch specs

* Added older arm version

* Added architecture explanation

* Pointed manifests to official image

* Removed xcfc files as requested in https://github.com/SystemRage/py-kms/pull/93#issuecomment-694937260

docker/docker-py3-kms-minimal/multi-arch-manifest-minimal.yaml

@@ -0,0 +1,21 @@
+image: pykmsorg/py-kms:minimal
+manifests:
+  - image: pykmsorg/py-kms:minimal-amd64
+    platform:
+      architecture: amd64
+      os: linux
+  - image: pykmsorg/py-kms:minimal-arm32v6
+    platform:
+      architecture: arm
+      os: linux
+      variant: v6
+  - image: pykmsorg/py-kms:minimal-arm32v7
+    platform:
+      architecture: arm
+      os: linux
+      variant: v7
+  - image: pykmsorg/py-kms:minimal-arm64v8
+    platform:
+      architecture: arm64
+      os: linux
+      variant: v8