Update pull_request_template.md

Author: dingsdax

.github/pull_request_template.md

@@ -8,6 +8,6 @@
 -->
 
 #### Reminders
-- Add GH Issue ID _&_ Linear ID
+- Add GH Issue ID _&_ Linear ID (if applicable)
 - PR title should use [conventional commit](https://develop.sentry.dev/engineering-practices/commit-messages/#type) style (`feat:`, `fix:`, `ref:`, `meta:`)
-- For external contributors: [CONTRIBUTING.md](../CONTRIBUTING.md), [Sentry SDK development docs](https://develop.sentry.dev/sdk/), [Discord community](https://discord.gg/Ww9hbqr)
+- For external contributors: [CONTRIBUTING.md](../CONTRIBUTING.md), [Sentry SDK development docs](https://develop.sentry.dev/sdk/), [Discord community](https://discord.gg/Ww9hbqr)