gh: update issue templates

.github/ISSUE_TEMPLATE/bug.md

@@ -0,0 +1,21 @@
+---
+name: Bug
+about: Exceptions and visual output errors
+---
+
+- [ ] I have marked all applicable categories:
+    + [ ] exception-raising bug
+    + [ ] visual output bug
+- [ ] I have visited the [source website], and in particular
+  read the [known issues]
+- [ ] I have searched through the [issue tracker] for duplicates
+- [ ] I have mentioned version numbers, operating system and
+  environment, where applicable:
+  ```python
+  import tqdm, sys
+  print(tqdm.__version__, sys.version, sys.platform)
+  ```
+
+[source website]: https://github.com/tqdm/tqdm/
+[known issues]: https://github.com/tqdm/tqdm/#faq-and-known-issues
+[issue tracker]: https://github.com/tqdm/tqdm/issues?q=

.github/ISSUE_TEMPLATE/config.yml

@@ -5,4 +5,4 @@ contact_links:
     about: Frequently asked questions and known issues
   - name: "StackOverflow#tqdm"
     url: https://stackoverflow.com/questions/tagged/tqdm
-    about: "Stack Overflow questions tagged #tqdm"
+    about: How-To questions

.github/ISSUE_TEMPLATE/enhancement.md

@@ -1,11 +1,9 @@
 ---
-name: Issue
-about: Use this template for reporting issue(s)
+name: Enhancement
+about: Feature requests and documentation improvements
 ---
 
 - [ ] I have marked all applicable categories:
-    + [ ] exception-raising bug
-    + [ ] visual output bug
     + [ ] documentation request (i.e. "X is missing from the documentation." If instead I want to ask "how to use X?" I understand [StackOverflow#tqdm] is more appropriate)
     + [ ] new feature request
 - [ ] I have visited the [source website], and in particular