[RN] Use of embedded OpenVSX registry requires CheCluster configuration

= Embedded OpenVSX registry by default With this update, the default registry for extensions for Microsoft Visual Studio Code - Open Source is the embedded OpenVSX registry, which is included in the devfile registry container. Before this update, the default was the public registry at ` https://open-vsx.org `. Administrators have two possible methods for changing this configuration: * Set the `CheCluster` object's `spec.components.pluginRegistry.openVSXURL` to ` https://open-vsx.org ` or another custom registry. * Arrange with your network administrator to configure the corporate proxy to allow access to the URLs required by the online registry. These URLs include, but are not limited to, the following: + ** open-vsx.org ** openvsxorg.blob.core.windows.net ** vscode-cdn.net + If you build a custom plugin registry using OpenVSX resources, the same proxy rules are required.