chore: update pr template for v5.3 (pingcap#6730) (pingcap#6734)

.github/pull_request_template.md

@@ -19,6 +19,7 @@ By default, **CHOOSE MASTER ONLY** so your changes will be applied to the next T
 For details, see [tips for choosing the affected versions](https://github.com/pingcap/docs/blob/master/CONTRIBUTING.md#guideline-for-choosing-the-affected-versions).
 
 - [ ] master (the latest development version)
+- [ ] v5.3 (TiDB 5.3 versions)
 - [ ] v5.2 (TiDB 5.2 versions)
 - [ ] v5.1 (TiDB 5.1 versions)
 - [ ] v5.0 (TiDB 5.0 versions)

CONTRIBUTING.md

@@ -34,6 +34,7 @@ Currently, we maintain the following versions of TiDB documentation, each with a
 | Docs branch name | Version description |
 | :--- | :--- |
 | `master` branch | the latest development version |
+| `release-5.3` branch | the 5.3 stable version |
 | `release-5.2` branch | the 5.2 stable version |
 | `release-5.1` branch | the 5.1 stable version |
 | `release-5.0` branch | the 5.0 stable version |
@@ -53,6 +54,7 @@ Currently, we maintain the following versions of TiDB documentation, each with a
 - If your changes apply to only one docs version, just submit a PR to the corresponding version branch.
 
 - If your changes apply to multiple docs versions, you don't have to submit a PR to each branch. Instead, after you submit your PR, trigger the ti-chi-bot to submit a PR to other version branches by adding one or several of the following labels as needed. Once the current PR is merged, ti-chi-bot will start to work.
+    - `needs-cherry-pick-5.3` label: ti-chi-bot will submit a PR to the `release-5.3` branch.
     - `needs-cherry-pick-5.2` label: ti-chi-bot will submit a PR to the `release-5.2` branch.
     - `needs-cherry-pick-5.1` label: ti-chi-bot will submit a PR to the `release-5.1` branch.
     - `needs-cherry-pick-5.0` label: ti-chi-bot will submit a PR to the `release-5.0` branch.

README.md

@@ -24,6 +24,7 @@ Currently, we maintain the following versions of TiDB documentation in different
 | Branch name | TiDB docs version |
 | :---------|:----------|
 | [`master`](https://github.com/pingcap/docs/tree/master) | The latest development version |
+| [`release-5.3`](https://github.com/pingcap/docs/tree/release-5.3) | 5.3 stable version |
 | [`release-5.2`](https://github.com/pingcap/docs/tree/release-5.2) | 5.2 stable version |
 | [`release-5.1`](https://github.com/pingcap/docs/tree/release-5.1) | 5.1 stable version |
 | [`release-5.0`](https://github.com/pingcap/docs/tree/release-5.0) | 5.0 stable version |