chore: add issue template (#2619)

# Description

Adding a basic issue template, and redirecting people to the forum for questions about dfx use and to discussions for feature requests.

First step of [SDK-743](https://dfinity.atlassian.net/browse/SDK-743)

# How Has This Been Tested?

Can't be tested AFAIK

# Checklist:

- [x] The title of this PR complies with [Conventional Commits](https://www.conventionalcommits.org/en/v1.0.0/).
- [ ] I have edited the CHANGELOG accordingly.
- [ ] I have made corresponding changes to the documentation.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,39 @@
+---
+name: Bug Report
+about: Create a bug report for dfx.
+labels: needs-triage
+---
+<!--
+Thank you for filing a bug report! 🐛 Please provide a short summary of the bug,
+along with any information you feel relevant to replicating the bug.
+-->
+
+I tried the following:
+
+1. <step 1>
+2. <step 2>
+
+I expected to see this happen: *explanation*
+
+Instead, this happened: *explanation*
+
+### Meta
+
+`dfx --version`:
+```
+<version>
+```
+
+<!--
+If possible, please add log output using the --verbose flag.
+This will make debugging a lot easier.
+-->
+<details><summary>Further log output</summary>
+<p>
+
+```
+<log output>
+```
+
+</p>
+</details>

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,8 @@
+blank_issues_enabled: true
+contact_links:
+  - name: Question about dfx use
+    url: https://forum.dfinity.org/
+    about: Please ask and answer questions about how to use dfx in the developer forum.
+  - name: Feature Request
+    url: https://github.com/dfinity/sdk/discussions
+    about: Please create and upvote feature requests in Discussions