Fix typos in CONTRIBUTING.md
Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this [failed invocation](https://github.com/tensorflow/tensorflow/pull/60290/checks?check_run_id=12660438542) of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request. Please don't use "add file"/"update file"/"fix file"/etc. commit messages. These are hard to reason about when looking at the history of the file/repository. Instead, please write explanatory git commit messages.

The commit message is also the title of the PR if the PR has only one commit. It is thus twice important to have commit messages that are relevant, as PRs would be easier to understand and easier to analyze in search results.

For how to write good quality git commit messages, please consult https://cbea.ms/git-commit/  Hi @AspireVenom Can you please check @mihaimaruseac's comments and keep us posted ? Thank you! PR title changed, commit message not. But let's take it as it is and future commits would follow guidelines.
Changed a couple of grammatical and spelling things within this document.