Replace yaml issue templates with markdown templates (#287)

## Description

Replaces the issue forms with the old markdown issue templates. Some
details have changed too.

I've found the issue forms to be inflexible and the interface a bit
clunky. We can switch back if the situation improves.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,40 @@
+---
+name: Bug Report
+about: Is something not working correctly?
+title: ''
+labels: bug, triage
+assignees: ''
+---
+
+## Valence Version
+
+The commit hash or release number of the version you're using.
+
+## What You Did
+
+Describe how you arrived at the problem. If you can, provide a minimal reproducible example in the details below.
+
+<details>
+
+<summary>Playground</summary>
+
+```rust
+PASTE YOUR PLAYGROUND CODE HERE
+```
+
+</details>
+
+## What Went Wrong
+
+What were you expecting and what actually happened?
+
+## Additional Information
+
+Other information that can be used to further reproduce or isolate the problem.
+This commonly includes:
+
+- theories about what might be going wrong
+- links to related bugs, PRs or discussions
+- workarounds that you used
+- screenshots
+- logs

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -1,41 +0,0 @@
-name: Report a Bug
-description: Is there something not working like you expected? Let us know!
-labels: [bug, triage]
-body:
-  - type: input
-    attributes:
-      label: Valence Version
-      description: What version of Valence are you using? If you are targeting a specific commit or branch, put that instead.
-      placeholder: Version, branch, or commit hash.
-    validations:
-      required: true
-  - type: textarea
-    attributes:
-      label: Current Behavior
-      description: A concise description of what you're experiencing. Include any screenshots or additional information here.
-    validations:
-      required: false
-  - type: textarea
-    attributes:
-      label: Expected Behavior
-      description: A concise description of what you expected to happen. 
-    validations:
-      required: true
-  - type: textarea
-    attributes:
-      label: Steps To Reproduce
-      description: Steps to reproduce the behavior.
-      placeholder: |
-        1. Create a server using my sample
-        2. Do this...
-        3. Do that...
-        4. See error
-    validations:
-      required: true
-  - type: textarea
-    attributes:
-      label: Minimal Reproducible Example
-      description: A minimal example that exhibits the behavior. If you have a playground, paste it here. If the problem can be reproduced with one of the examples, just indicate which one instead.
-      render: Rust
-    validations:
-      required: false

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,24 @@
+---
+name: Feature Request
+about: Do you have an idea for a new feature?
+title: ''
+labels: enhancement
+assignees: ''
+---
+
+## Describe the problem related to your feature request.
+
+A description of what the problem is.
+
+## What solution would you like?
+
+The solution you propose for the problem presented.
+
+## What alternative(s) have you considered?
+
+Other solutions to solve and/or work around the problem presented.
+
+## Additional context
+
+Any other information you would like to add such as related previous work,
+screenshots, benchmarks, etc.

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -1,22 +0,0 @@
-name: Feature Request
-description: Do you have an idea for a new feature? Let us know!
-labels: [enhancement]
-body:
-  - type: textarea
-    attributes:
-      label: Describe the problem related to your feature request.
-      description: A clear description of what the problem is.
-    validations:
-      required: true
-  - type: textarea
-    attributes:
-      label: Describe the solution you would like.
-      description: The solution you propose for the problem presented.
-    validations:
-      required: true
-  - type: textarea
-    attributes:
-      label: Additional context
-      description: Add any other context or screenshots about the feature request here.
-    validations:
-      required: false

.github/pull_request_template.md

@@ -1,6 +1,6 @@
 ## Description
 
-Describe the changes you've made. Link to any issues that this PR fixes or addresses.
+Describe the changes you've made. Link to any issues this PR fixes or addresses.
 
 ## Test Plan