Docs: complete cut-off sentence in “Preparing a pull request” section

[sdass1918]

Fixes #3596

This PR fixes a cut-off sentence in contributor_docs/preparing_a_pull_request.md under the “Pull Request Templates” section.

Changes:
Completed the missing text explaining the verification steps contributors should check before submitting a PR.

I have verified that this pull request:

• has no linting errors (npm run lint)
• has no test errors (npm run test)
• is from a uniquely-named feature branch and is up to date with the develop branch.
• is descriptively named and links to an issue number, i.e. Fixes #123
• meets the standards outlined in the accessibility guidelines

[yugalkaushik]

@sdass1918 Thank you for the PR, I think along with the code related to this PR you pushed some translation code, Please review them once.

[sdass1918]

@yugalkaushik
Thanks for pointing that out, I’ve removed the extra translation files and kept only the doc changes.