Modify templates to have warnings & add config.yml for issues

.github/ISSUE_TEMPLATE/bug_report.md

@@ -4,6 +4,19 @@ about: Create a report to help us improve
 
 ---
 
+<!--
+
+IMPORTANT! READ
+
+Any spam issues will be deleted.
+Issues are not a place to go ask support questions.
+
+Please post **confirmed** bugs when possible.
+
+Please mark the checkbox below (Use "x" to fill the checkboxes, example: [x])
+-->
+- [ ] I have read the specified guidelines for issues
+
 **Describe the bug**
 A clear and concise description of what the bug is.
 

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,8 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Mailing list
+    url: https://lists.sr.ht/~tenacity/tenacity-discuss
+    about: Mailing list on Sourcehut for questions. Spam is not accepted.
+  - name: Discussions
+    url: https://github.com/tenacityteam/tenacity/discussions/categories/q-a
+    about: Please ask questions here. You may also use IRC (#tenacity on irc.libera.chat)

.github/ISSUE_TEMPLATE/feature_request.md

@@ -4,6 +4,20 @@ about: Suggest an idea for this project
 
 ---
 
+<!--
+
+IMPORTANT! READ
+
+Any spam issues will be deleted.
+Issues are not a place to go ask support questions.
+
+Please make sure your feature request contains as many details
+as possible.
+
+Please mark the checkbox below (Use "x" to fill the checkboxes, example: [x])
+-->
+- [ ] I have read the specified guidelines for issues
+
 **Is your feature request related to a problem? Please describe.**
 A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
 

.github/pull_request_template.md

@@ -1,11 +1,24 @@
+<!--
+
+IMPORTANT! READ
+
+Any spam PRs will be closed.
+Please make sure your PR
+complies with the requirements.
+-->
+
 Resolves: *(direct link to the issue)*
 
 *(short description of the changes and the motivation to make the changes)*
 
-<!-- Use "x" to fill the checkboxes below like [x] -->
+<!-- Use "x" to fill the checkboxes below like [x]
+an asterisk (*) after the entry indicates required
+-->
 
-- [ ] The code in this pull request is licensed under "GPLv2 or any later version"
+- [ ] The code in this pull request is licensed under "GPLv2 or any later version"\*
 - [ ] I made sure the code compiles on my machine
-- [ ] I made sure there are no unnecessary changes in the code
-- [ ] I made sure the title of the PR reflects the core meaning of the issue you are solving
-- [ ] I made sure the commit message(s) contain a description and answer the question "Why do those changes fix that particular issue?" or "Why are those changes really necessary as improvements?"
+- [ ] I made sure there are no unnecessary changes in the code\*
+- [ ] I made sure the title of the PR reflects the core meaning of the issue you are solving\*
+- [ ] I made sure the commit message(s) contain a description and answer the question "Why do those changes fix that particular issue?" or "Why are those changes really necessary as improvements?"\*
+
+\* indicates required