Refactor: convert Docker support warning to single file

src/theme/MDXComponents.js

@@ -10,6 +10,7 @@ import CNIPopularityTable from '/shared-files/_cni-popularity.md';
 import DeprecationOPAGatekeeper from '/shared-files/_deprecation-opa-gatekeeper.md';
 import DeprecationWeave from '/shared-files/_deprecation-weave.md';
 import DeprecationHelm2 from '/shared-files/_deprecation-helm2.md';
+import DockerSupportWarning from '/shared-files/_docker-support-warning.md';
 
 export default {
   // Re-use the default mapping
@@ -25,4 +26,5 @@ export default {
   DeprecationOPAGatekeeper,
   DeprecationWeave,
   DeprecationHelm2,
+  DockerSupportWarning,
 };