[CI]Update gemini config (#6447)

Update gemini config to make it more useful

- vLLM version: v0.14.1
- vLLM main:
dc917cceb8

Signed-off-by: wangxiyuan <wangxiyuan1007@gmail.com>

.gemini/config.yaml

@@ -1,6 +1,9 @@
 # https://developers.google.com/gemini-code-assist/docs/customize-gemini-behavior-github
 have_fun: false  # Just review the code
+memory_config:
+  disabled: false
 code_review:
   comment_severity_threshold: HIGH  # Reduce quantity of comments
   pull_request_opened:
-    summary: false  # Don't summarize the PR in a separate comment
+    help: true  # Add a help comment to the PR
+    summary: true  # Summarize the PR in a separate comment

.gemini/styleguide.md

@@ -0,0 +1,51 @@
+# Pull Request Summary Style Guide
+
+## Pull Request Summary Format
+
+The summary should follow the format:
+
+   ```markdown
+    ### What this PR does / why we need it?
+    <!--
+    - Please clarify what changes you are proposing. The purpose of this section is to outline the changes and how this PR fixes the issue.
+    If possible, please consider writing useful notes for better and faster reviews in your PR.
+
+    - Please clarify why the changes are needed. For instance, the use case and bug description.
+
+    - Fixes #
+    -->
+
+    ### Does this PR introduce _any_ user-facing change?
+    <!--
+    Note that it means *any* user-facing change including all aspects such as API, interface or other behavior changes.
+    Documentation-only updates are not considered user-facing changes.
+    -->
+
+    ### How was this patch tested?
+    <!--
+    CI passed with new added/existing test.
+    If it was tested in a way different from regular unit tests, please clarify how you tested step by step, ideally copy and paste-able, so that other reviewers can test and check, and descendants can verify in the future.
+    If tests were not added, please describe why they were not added and/or why it was difficult to add.
+    -->
+   ```
+
+## Pull Request Title Format
+
+The summary should also refresh the Pull Request Title to follow the format:
+
+    ```txt
+    [Branch][Module][Action] Pull Request Title
+    ```
+
+- Branch: The branch name where the PR is based.
+- Module: The module or component being changed. It includes but is not limited to the following:
+    - [Attention]
+    - [Ops]
+    - [Doc]
+    - [Test]
+    - [CI]
+    - [Benchmark]
+- Action: The action being performed. It includes but is not limited to the following:
+    - [BugFix]
+    - [Feature]
+    - [Misc]