Update issue templates

.github/ISSUE_TEMPLATE/add-or-request-example-of-code.md

@@ -0,0 +1,24 @@
+---
+name: Add or request example of code
+about: Suggest an example idea for this project
+title: ''
+labels: documentation, enhancement, good first issue
+assignees: ''
+
+---
+
+**Describe the `multipers` application that you'd like.**
+I am currently working on [...] and this example is not treated in the example zoo of `multipers`.
+
+**Link to code and dataset**
+Resources to run the code (if you have working code). 
+If the example is not too long, you can give it inline, 
+but the preferred way is attaching files.
+```python
+import multipers as mp
+[...]
+```
+
+**Checks.**
+ - [ ] I have checked that this example does not exist in the example zoo of the documentation
+ - [ ] I am willing to do give a working  (Thank you!) by providing a python notebook of this example, and/or do a pull request.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -31,3 +31,8 @@ instead of
  - version [e.g. 2.0, or commit hash if compiled]:
  - C++ compiler (if compiled from source) [e.g., gcc 12.1, clang 18.1]:
  - dependencies versions or `.yml` file [e.g., numpy=1.24, gudhi=3.9]
+
+**Checks.**
+ - [ ] I have a working environment (i.e., `pytest multipers` passes)
+ - [ ] I have checked that the bug is not already present in the issue tracker
+ - [ ] I am willing to do a PR to fix this issue (Thank you!)

.github/ISSUE_TEMPLATE/feature_request.md

@@ -16,5 +16,7 @@ Ideally, this could take the form of
 ```python
 import multipers as mp
 [...]
-mp.stuff.new_function(something) # should return `stuff`
+mp.stuff.new_function(something) # should ideally return `stuff`
 ```
+**Checks.**
+ - [ ] I have checked the issue tracker and the example zoo (in the documentation), and this idea is not covered