ci: add 'take' bot like main Arrow repo

.github/workflows/comment_bot.yml

@@ -0,0 +1,44 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+
+
+name: Comment Bot
+
+on:
+  issue_comment:
+    types:
+      - created
+      - edited
+
+jobs:
+  issue_assign:
+    name: "Assign issue"
+    permissions:
+      issues: write
+    if: github.event.comment.body == 'take'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            github.rest.issues.addAssignees({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: context.payload.issue.number,
+                assignees: context.payload.comment.user.login
+            });

CONTRIBUTING.md

@@ -274,6 +274,14 @@ $ cargo test
 
 ## Opening a Pull Request
 
+Before opening a pull request:
+
+1. Please check if there is a corresponding issue (_and if not, please make one_).
+2. Assign the issue to yourself by commenting "take" in the issue.
+3. At the bottom of the PR description, add `Closes #NNNN` where `NNNN` is the
+   issue number, so that the issue gets linked to your PR properly. ("Fixes"
+   and other keywords that GitHub recognizes are also OK, of course.)
+
 Before opening a pull request, please run the static checks, which are
 enforced via [`pre-commit`](https://pre-commit.com/).  This will run
 linters, formatters, and other analysis.  For example: