[CI] Add e2e test frame work and doctest (#730)

### What this PR does / why we need it?
Add quickstart doctest CI

### Does this PR introduce _any_ user-facing change?
no

### How was this patch tested?
- CI passed
- Run `/vllm-ascend/tests/e2e/run_doctests.sh`
Related: https://github.com/vllm-project/vllm-ascend/issues/725

Signed-off-by: Yikun Jiang <yikunkero@gmail.com>

tests/e2e/doctests/001-quickstart-test.sh

@@ -0,0 +1,55 @@
+#!/bin/bash
+
+#
+# Copyright (c) 2025 Huawei Technologies Co., Ltd. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# This file is a part of the vllm-ascend project.
+#
+
+function simple_test() {
+  # Do real import test
+  python3 -c "import vllm; print(vllm.__version__)"
+}
+
+function quickstart_offline_test() {
+  export VLLM_USE_MODELSCOPE=true
+  # Do real script test
+  python3 "${SCRIPT_DIR}/../../examples/offline_inference_npu.py"
+}
+
+function quickstart_online_test() {
+  export VLLM_USE_MODELSCOPE=true
+  vllm serve Qwen/Qwen2.5-0.5B-Instruct &
+  wait_url_ready "vllm serve" "localhost:8000/v1/models"
+  # Do real curl test
+  curl http://localhost:8000/v1/completions \
+    -H "Content-Type: application/json" \
+    -d '{
+        "model": "Qwen/Qwen2.5-0.5B-Instruct",
+        "prompt": "Beijing is a",
+        "max_tokens": 5,
+        "temperature": 0
+    }' | python3 -m json.tool
+  VLLM_PID=$(pgrep -f "vllm serve")
+  _info "===> Try kill -2 ${VLLM_PID} to exit."
+  kill -2 "$VLLM_PID"
+  wait_for_exit "$VLLM_PID"
+}
+
+_info "====> Start simple_test"
+simple_test
+_info "====> Start quickstart_offline_test"
+quickstart_offline_test
+_info "====> Start quickstart_online_test"
+quickstart_online_test