Add implementation issue template

.github/ISSUE_TEMPLATE/implementation-ticket.md

@@ -0,0 +1,36 @@
+---
+name: 🛠️ Implementation
+about: This is an implementation ticket intended for use by the maintainers of dbt-core
+title: '[<project>] <title>'
+labels: user_docs
+---
+
+[x] I am a maintainer of dbt-core
+
+<!---
+  A couple reminders: 
+
+   * Remove the user_docs label if the scope of this work does not require changes to https://docs.getdbt.com/docs (no end-user interface (e.g. yml spec, CLI, error messages) or functionality changes)
+
+    * Link any blocking issues in the "Blocked on" field under the "Core devs & maintainers" project.
+-->
+
+### Short description
+<!---
+Describe of the scope of the ticket, a high-level implementation approach and any tradeoffs to consider
+-->
+
+
+### Acceptance Criteria
+
+<!---
+What is the definition of done for this ticket? Include any relevant edge cases and/or test cases
+-->
+- ...
+- ...
+
+ ### Context
+ <!---
+Provide the "why", motivation, and alternative approaches considered -- linking to previous refinement issues, spikes, Notion docs as appropriate
+-->
+- [link]