Add issue templates and a pull-request template

[0xDevNinja]

Problem

The repository has no issue templates and no pull-request template (.github/ISSUE_TEMPLATE/ and .github/PULL_REQUEST_TEMPLATE.md are absent). As a result:

• Bug reports arrive with inconsistent detail. The high-signal ones (e.g. Windows Remotion render fails when --props is passed as a separate argument #172) manually include OS / pipeline / runtime / error / repro, but many issues are low-context or off-topic (e.g. Love #117, What does he mean by "open in the project"? #144, copilot/fix-36305https://github.com/moraesc/docs.git #122/Issue #122 created #123), which adds triage load on a fast-growing tracker.
• There's no structured prompt steering reporters to the right channel — the project already uses GitHub Discussions for Q&A / Ideas / Show-and-Tell, but nothing routes questions there.

Proposed Solution

Add GitHub community templates:

1. .github/ISSUE_TEMPLATE/bug_report.yml — a form capturing OS, pipeline, runtime, repro steps, expected vs actual, and logs (mirrors the fields the best existing bug reports already use).
2. .github/ISSUE_TEMPLATE/feature_request.yml — problem / proposed solution / alternatives.
3. .github/ISSUE_TEMPLATE/config.yml — routes questions and show-and-tell to the existing GitHub Discussions categories.
4. .github/PULL_REQUEST_TEMPLATE.md — summary / linked issue / testing-done / checklist.

Purely additive, no source changes. I'll open a PR.