User Feedback: Document issue creation integrations

[bruno-garcia]

User Feedback docs doesn't yet mention the ability to create an issue on your connected ticket system such as GitHub, Jira, GitLab, etc.

It's also possible to automate issue creation, so that all feedback received by Sentry results in a ticket in your preferred system.

[getsantry[bot]]

Routing to @getsentry/product-owners-user-feedback for triage ⏲️