docs: update

grpc/scripts/gen.bat

@@ -58,7 +58,7 @@ for %%A in (%*) do (
     @echo off
   )
   if "%%A"=="docs" (
-    set plugin=protoc-gen-ts
+    set plugin=protoc-gen-doc
     where /q !plugin! || echo missing !plugin! && exit /B
     set out=..\..\docs
     if not exist !out! mkdir !out!

grpc/scripts/gen.sh

@@ -93,7 +93,7 @@ for aug in $@; do
       $async_tag
   fi
   if [ $aug == "docs" ]; then
-    plugin=protoc-gen-ts
+    plugin=protoc-gen-doc
     plugin_path=$(which $plugin)
     if [ $? -ne 0 ]; then
       echo "missing plugin: $plugin" && exit