fix(docs): Corrected filename of the PR template

[ItsIgnacioPortal]

In its previous file position, the PR template would only be used if a contributor were to click a link specifically crafted to use that PR. With this PR, the PR template will be used every single time someone creates a pull request.

See: https://docs.github.com/en/communities/using-templates-to-encourage-useful-issues-and-pull-requests/creating-a-pull-request-template-for-your-repository

In the future, when the UI for picking a PR template is added into github, this will be revised to add specific templates for "wordlist" PRs, "documentation" PRs, and "CI/CD" PRs.

The relevant github discussion is https://github.com/orgs/community/discussions/42499