Replace plural pronouns (we, our, us) with singular/project voice
throughout documentation files to represent a singular developer
perspective.
Changes:
- CONTRIBUTING.md: Replace "We are" with "This project is",
"We use" with "This project uses", "our" with "the"
- README.md: Replace "our" with "the", add OS to bug report checklist
- docs/VERSION_HISTORY.md: Replace "we reset" with passive voice
"the version was reset"
