Fix minor grammar issues

[popmechanic]

No description provided.

[Flavien]

Thanks a lot for the corrections. The changes look good to me. There is just one small thing before I merge: can you start the commit message with a verb in infinitive form, for consistency with the rest of the project, and with other open source projects, for example:

• Make minor gramatical edits or
• Fix minor grammatical errors

Also, I think grammatical should have two ms.

[popmechanic]

Excellent, thanks for the feedback. I amended the commit messages (and corrected the spelling of grammar;).

[Flavien]

Can you also change the commit title? You can use git amend to do that, then you'll need to force push to GitHub.