mark httpclient support as experimental (#9016)

Author: wing328

docs/generators/csharp-netcore.md

@@ -12,7 +12,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |disallowAdditionalPropertiesIfNotPresent|If false, the 'additionalProperties' implementation (set to true by default) is compliant with the OAS and JSON schema specifications. If true (default), keep the old (incorrect) behaviour that 'additionalProperties' is set to false by default.|<dl><dt>**false**</dt><dd>The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.</dd><dt>**true**</dt><dd>Keep the old (incorrect) behaviour that 'additionalProperties' is set to false by default.</dd></dl>|true|
 |hideGenerationTimestamp|Hides the generation timestamp when files are generated.| |true|
 |interfacePrefix|Prefix interfaces with a community standard or widely accepted prefix.| |I|
-|library|HTTP library template (sub-template) to use|<dl><dt>**httpclient**</dt><dd>HttpClient (https://docs.microsoft.com/en-us/dotnet/api/system.net.http.httpclient) (Beta support)</dd><dt>**restsharp**</dt><dd>RestSharp (https://github.com/restsharp/RestSharp)</dd></dl>|restsharp|
+|library|HTTP library template (sub-template) to use|<dl><dt>**httpclient**</dt><dd>HttpClient (https://docs.microsoft.com/en-us/dotnet/api/system.net.http.httpclient) (Experimental. May subject to breaking changes without further notice.)</dd><dt>**restsharp**</dt><dd>RestSharp (https://github.com/restsharp/RestSharp)</dd></dl>|restsharp|
 |licenseId|The identifier of the license| |null|
 |modelPropertyNaming|Naming convention for the property: 'camelCase', 'PascalCase', 'snake_case' and 'original', which keeps the original name| |PascalCase|
 |netCoreProjectFile|Use the new format (.NET Core) for .NET project files (.csproj).| |false|

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpNetCoreClientCodegen.java

@@ -301,7 +301,8 @@ public CSharpNetCoreClientCodegen() {
         regexModifiers.put('s', "Singleline");
         regexModifiers.put('x', "IgnorePatternWhitespace");
 
-        supportedLibraries.put(HTTPCLIENT, "HttpClient (https://docs.microsoft.com/en-us/dotnet/api/system.net.http.httpclient) (Beta support)");
+        supportedLibraries.put(HTTPCLIENT, "HttpClient (https://docs.microsoft.com/en-us/dotnet/api/system.net.http.httpclient) "
+                + "(Experimental. May subject to breaking changes without further notice.)");
         supportedLibraries.put(RESTSHARP, "RestSharp (https://github.com/restsharp/RestSharp)");
 
         CliOption libraryOption = new CliOption(CodegenConstants.LIBRARY, "HTTP library template (sub-template) to use");