Update plugin documentation and types to support ReadableStream in provider results

src/ts/plugins/plugins.ts

@@ -305,7 +305,7 @@ type EditFunction = (content:string) => string|null|undefined|Promise<string|nul
 type ReplacerFunction = (content:OpenAIChat[], type:string) => OpenAIChat[]|Promise<OpenAIChat[]>
 
 export const pluginV2 = {
-    providers: new Map<string, (arg:PluginV2ProviderArgument) => Promise<{success:boolean,content:string}> >(),
+    providers: new Map<string, (arg:PluginV2ProviderArgument) => Promise<{success:boolean,content:string|ReadableStream<string>}> >(),
     editdisplay: new Set<EditFunction>(),
     editoutput: new Set<EditFunction>(),
     editprocess: new Set<EditFunction>(),

src/ts/process/request.ts

@@ -1420,7 +1420,24 @@ async function requestPlugin(arg:RequestDataArgumentExtended):Promise<requestDat
     else if(!d.success){
         return {
             type: 'fail',
-            result: d.content
+            result: d.content instanceof ReadableStream ? await (new Response(d.content)).text() : d.content
+        }
+    }
+    else if(d.content instanceof ReadableStream){
+
+        let fullText = ''
+        const piper = new TransformStream<string, StreamResponseChunk>(  {
+            transform(chunk, control) {
+                fullText += chunk
+                control.enqueue({
+                    "0": fullText
+                })
+            }
+        })
+
+        return {
+            type: 'streaming',
+            result: d.content.pipeThrough(piper)
         }
     }
     else{