Add basic issue & PR templates

Author: Seelengrab

.github/ISSUE_TEMPLATE/bug.yaml

@@ -0,0 +1,53 @@
+name: Bug Report
+description: File a bug report
+title: "[Bug]: "
+labels: ["bug"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        If you have a question please search or post to the [Discussions tab](https://github.com/Seelengrab/Supposition.jl/discussions).
+        We use the GitHub issue tracker for bug reports and feature development only.
+  - type: textarea
+    id: what-happened
+    attributes:
+      label: What happened?
+      description: Please describe the steps you took and provide any code executed to reproduce the bug, as well as any error messages that were printed.
+      placeholder: |
+        I executed this function:
+        
+        ```julia
+        [...]
+        ````
+  
+        and encountered the following error/wrong/unexpected result:
+  
+        [...]
+    validations:
+      required: true
+  - type: textarea
+    id: expectation
+    attributes:
+      label: What did you expect to happen?
+      description: Please describe what you expected to happen.
+      placeholder: I expected the function to return `foobar`.
+    validations:
+      required: true
+  - type: textarea
+    id: version
+    attributes:
+      label: Version
+      description: What version of julia are you running?
+      placeholder: In the environment the bug occurred, please run `using InteractiveUtils; versioninfo()` and paste the output here.
+      render: shell
+    validations:
+      required: true
+  - type: textarea
+    id: version
+    attributes:
+      label: Version
+      description: What version of Supposition.jl are you using?
+      placeholder: In the environment the bug occurred, please run `import Pkg; Pkg.status()` and paste the output here.
+      render: shell
+    validations:
+      required: true

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: true
+contact_links:
+  - name: Question and/or feature request 
+    url: https://github.com/Seelengrab/Supposition.jl/discussions
+    about: Please ask and answer questions about Supposition.jl, as well as request features, on the Discussions tab.

.github/PULL_REQUEST_TEMPLATE/pull_request_template.md

@@ -0,0 +1,10 @@
+## PR Description
+
+What does this pull request implement?
+Please be as descriptive as possible!
+
+### PR Checklist
+
+ - [ ] Tests written
+ - [ ] Documentation expanded
+ - [ ] Feature ready for review (if false, please mark the PR as `Draft`!)