Fix jsdoc for performLazySirenAction, add templates for mixins

[awikkerink]

I feel like I'm approaching the 80/20 boundary, so I'm finally going to stop after this.

Maybe...

[github-actions[bot]]

PR Checklist:

Did you use a semver keyword in a commit message?

• [ ] Yes I used one in at least one of my commits
• [x] No but I will use a semver keyword in the commit message when I merge and squash

Did you paste the Jira ticket URL in the description?

• [ ] Yes
• [x] No as there's no corresponding Jira ticket

[d2l-github-release-tokens[bot]]

:tada: This PR is included in version 3.11.3 :tada:

The release is available on:

• GitHub release
• npm package (@latest dist-tag)

Your semantic-release bot :package::rocket: