Update issue templates (#960)

* Update issue templates

* Remove unused templates.

* Formatting

Author: drwpow

.github/ISSUE_TEMPLATE/bug-report.md

@@ -0,0 +1,34 @@
+---
+name: Bug report
+about: Unrelated to the OpenAPI schema (Node error, etc.)
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+**Description**
+
+_A brief description of the bug._
+
+```
+Paste full error message
+```
+
+| Name                 | Version                      |
+|:---------------------|:-----------------------------|
+| `openapi-typescript` | `x.x.x`                      |
+| Node.js              | `x.x.x`                      |
+| OS + version         | `macOS 13, Windows 11, etc.` |
+
+**Reproduction**
+
+_How can this be reproduced / when did the error occur?_
+
+**Expected result**
+
+_(in case it’s not obvious)_
+
+**Checklist**
+
+- [ ] I’m willing to open a PR (see [CONTRIBUTING.md](https://github.com/drwpow/openapi-typescript/blob/main/CONTRIBUTING.md))

.github/ISSUE_TEMPLATE/bug.md

@@ -0,0 +1,20 @@
+---
+name: Feature request
+about: Add missing functionality
+title: ''
+labels: enhancement, help wanted
+assignees: ''
+
+---
+
+**Description**
+
+_Brief description of the problem you’re trying to solve, and why this could be useful._
+
+**Proposal**
+
+_Outline the change to the library. If this is for the CLI, propose a flag name and/or workflow. If this is for Node API, propose how this would be consumed. Reference any prior art or similar examples._
+
+**Checklist**
+
+- [ ] I’m willing to open a PR for this (see [CONTRIBUTING.md](https://github.com/drwpow/openapi-typescript/blob/main/CONTRIBUTING.md))

.github/ISSUE_TEMPLATE/feature.md

@@ -0,0 +1,37 @@
+---
+name: Unsupported schema syntax
+about: Part of the OpenAPI spec isn’t generating as expected (or at all)
+title: ''
+labels: bug
+assignees: ''
+
+---
+
+**Description**
+
+_A brief description of the issue. _
+
+_[Link to the OpenAPI version & spec description](#)_
+
+**OpenAPI**
+
+```yaml
+# Your OpenAPI schema (can be a stub)
+```
+
+**Generated TS**
+
+```ts
+// What’s generated in the current version (or put “nothing” if it’s skipped)
+```
+
+**Expected TS*
+
+```ts
+// What you’d like to see generated
+```
+
+**Checklist**
+
+- [ ] My OpenAPI schema passes a validator
+- [ ] I’m willing to open a PR for this (see [CONTRIBUTING.md](https://github.com/drwpow/openapi-typescript/blob/main/CONTRIBUTING.md))